Dog DNA probed for clues to human psychiatric ills

Pet project hunts genetic links to behaviour by polling owners on their companions’ quirks.

Heidi Ledford. Tail-chasing in dogs is suspected to share genetic roots with human obsessive–compulsive disorder.

Addie plays hard for an 11-year-old greater Swiss mountain dog — she will occasionally ignore her advanced years to hurl her 37-kilogram body at an unwitting house guest in greeting. But she carries a mysterious burden: when she was 18 months old, she started licking her front legs aggressively enough to wear off patches of fur and draw blood.

Addie has canine compulsive disorder — a condition that is thought to be similar to human obsessive–compulsive disorder (OCD). Canine compulsive disorder can cause dogs to chase their tails for hours on end, or to suck on a toy or body part so compulsively that it interferes with their eating or sleeping.

Addie may soon help researchers to determine why some dogs are more prone to the disorder than others. Her owner, Marjie Alonso of Somerville, Massachusetts, has enrolled her in a project called Darwin’s Dogs, which aims to compare information about the behaviour of thousands of dogs against the animals’ DNA profiles. The hope is that genetic links will emerge to conditions such as canine compulsive disorder and canine cognitive dysfunction — a dog analogue of dementia and possibly Alzheimer’s disease. The project organizers have enrolled 3,000 dogs so far, but hope to gather data from at least 5,000, and they expect to begin analysing DNA samples in March.

“It’s very exciting, and in many ways it’s way overdue,” says Clive Wynne, who studies canine behaviour at Arizona State University in Tempe.

Researchers have long struggled to find genetic links to human psychiatric disorders by analysing DNA samples from thousands of people. Those efforts have in recent years met with some success in schizophrenia and depression. But for some conditions, including OCD, not a single robust genetic link has been sifted from the background noise of normal genetic variation.

Human studies are difficult in part because the species is so genetically diverse, says Wynne. Dogs, however, are more genetically homogeneous. Selected over thousands of years for particular characteristics, they display less genetic variation than do humans. Pure-bred dogs, in particular, have been rendered highly genetically consistent to achieve a homo­genous appearance and behaviour.

Dogs also live side-by-side with humans, which some think can make them a better model for human disorders than mice living in a laboratory cage.

These qualities have made dogs attractive targets for studies of analogues to human ailments, including epilepsy, cancer and various psychiatric disorders. Border collies, for example, may over-react to loud noises in a manner akin to people with anxiety disorders. Geneticist Elinor Karlsson of the University of Massachusetts Medical School in Amherst and her colleagues have studied canine compulsive disorder, a condition that is particularly common in certain breeds, including Dobermann pinschers. Their studies in 150 dogs have found possible links to four genes that encode proteins that act in the brain (R. Tang et al. Genome Biol. 15, R25; 2014).

To expand on those results, Karlsson has decided to go big. Limiting her studies to specific breeds would make it easier to pick out some genetic links, but others might be missed. So Karlsson and her colleagues, including Jesse McClure, a former dog trainer for the US Marine Corps, decided to collect data from mongrels as well as pure-bred dogs and to crowdsource the data collection.

That focus on mixed-breed dogs is unusual but shrewd, says Adam Boyko, a geneticist at Cornell University in Ithaca, New York. Although more than half of the dogs in the United States are mongrels, genetic studies tend to focus on pure-bred animals. “Genetics often deals with the interactions between genes,” says Boyko. “And if you want to truly understand those, you want to study individuals where you’ve shuffled up the genes.”

Human participants in Darwin’s Dogs, which launched last October, answer about 130 questions about their pets’ behaviour. The questions cover everything from ‘Does your dog generally enjoy life?’ (the answer, says Karlsson, is overwhelmingly ‘yes’) to ‘Does your dog cross its paws when it lies down?’. Some questions were inspired by surveys that assess impulsivity in humans. Other questions have been suggested by Alonso, who is the executive director of the International Association of Animal Behavior Consultants in Cranberry Township, Pennsylvania, and by other dog trainers on the basis of observations made over decades of working with animals that have behavioural problems.

Karlsson says that she is thinking of expanding the list of questions even further. “Fortunately, it turns out that people love to talk about their dogs,” she says.

Ultimately, the success of the project may hinge on the quality of those surveys and the specificity of the questions asked, says Wynne. Asking owners whether their dog is happy, for example, could yield mixed results. “One person’s unhappy dog is another person’s comfortably resting dog,” he says. “A good question would be: ‘Does your dog poop on the carpet?’ Because poop on the carpet is pretty damn clear.”

It is still unclear how useful the results from dogs will be in shedding light on human behavioural variation. Karlsson is hopeful that even if different genes are involved in the two species, they may converge on the same cellular pathways. Gerald Nestadt, a psychiatrist who specializes in OCD at Johns Hopkins University in Baltimore, Maryland, notes that affected animals often display only one type of compulsive behaviour, whereas a human with OCD will typically have several.

Even so, he adds, the field is hungry for any leads it can get. “Anything that will help is worth trying,” he says. “I think this project is a great idea.”

For their part, Alonso and other participants are eager to learn more about their own dogs and why they behave the way they do. Miranda Workman of Buffalo, New York, enrolled her three dogs — Zeus, Athena and Sherlock — into the study, in part to gain insight into their behavioural quirks. Although Athena, a 34-kilogram Dutch shepherd, was bred to be a dedicated herding and guarding dog, she has a jovial side that is not often found in her breed. And Sherlock, a Jack Russell, is more shy and sensitive than other terriers.

“I have some dogs that don’t necessarily fit the stereotype,” says Workman. “Is it their environment that’s different or are they different? It will be fun to find out why they are that way.”

Nature 529, 446–447 (28 January 2016) doi:10.1038/529446a   Nature  Original web page at Nature


* Vaccine study shapes plan to wipe out rabies in free-roaming dogs

Rabies could be eradicated from street dogs in India with the help of a new smartphone app, a study has shown. Researchers are using the app to track free-roaming dogs that have been vaccinated against rabies.

Monitoring them in this way has enabled vets to vaccinate 70 per cent of the dog population in the City of Ranchi — the threshold needed to minimise the risk that the disease is passed to people.

Adopting the approach more widely could help to eliminate rabies from people and animals, the researchers say.

Teams vaccinated more than 6000 dogs in 18 districts of the city of Ranchi, India. They surveyed the number of marked, vaccinated and unmarked, unvaccinated dogs to monitor the proportion of animals that had received the vaccine.

A bespoke smartphone app — called the Mission Rabies app — was developed for researchers to instantly upload information about the animals vaccinated, including their exact location.

In areas where coverage fell below 70 per cent, catching teams were re-deployed to vaccinate more dogs until the target was achieved.

The study was led by Mission Rabies in collaboration with researchers from the Royal (Dick) School of Veterinary Studies at the University of Edinburgh.

Rabies remains a global problem that leads to the suffering and premature deaths of over 50,000 people and many times more dogs each year. The disease has been eliminated from many countries through mass vaccination of the dog population. However, rabies elimination remains challenging in countries where the majority of dogs are allowed to roam freely.

Previous research has shown that vaccinating just 70 per cent of the dog population is enough to cut the risk of rabies infections in people.

Dr Richard Mellanby, a Wellcome Trust Clinical Fellow at the Royal (Dick) School of Veterinary Studies, said: “We have shown that mobile technology can help to monitor the efforts of large scale vaccination of free roaming dogs in real time This allows us to identify areas where vaccination needs to be increased to meet the 70 per cent threshold and cut the risk of the disease being passed to people.”

The study is published in the journal BMC Infectious Diseases. It was funded by the Dogs Trust with additional resources provided by Ranchi Municipal Council. All vaccines used in the project were donated by MSD Animal Health.   Science Daily  Original web page at Science Daily


* Two thirds of cattle attacks on people involve dogs, new study finds

Dog owners are being urged to remember to be vigilant with their pets when walking near cows in the countryside, following a new review into cattle attacks by the University of Liverpool.

Anecdotal media and hospital reports of cattle causing injury or death to members of the public have existed for many years, but until now no further investigation has been carried out examining why these events may occur.

This project reviewed details of negative interactions between the public and cattle, to identify risk factors for cattle attacks, and highlight the availability and usefulness of guidance on walking among livestock.

A total of 54 cattle attacks were reported in the UK media between 1993 and 2013 and, of these, approximately one in four were fatal and two-thirds involved dogs.

Dr Carri Westgarth, a dog behaviour expert at the University’s Institute of Infection and Global Health, said: “We found that walking with dogs among cows, particularly with calves present, was a common factor for an attack.

“One theory for this is that the cows may feel particularly threatened by dogs, especially if they have young to protect. People then try to protect their dogs, which can lead to a tragic incident occurring.”

The review of published literature, newspaper articles and web pages also highlighted that injuries from cattle are a significant and under-reported public health risk.

Dr Marie McIntyre, who co-authored the review, said: “There is currently no official system in place for reporting attacks, so it is highly likely that there have been far more incidents than we know about. Further work is needed to fully assess the public health impact of this issue.”

There are approximately 300,000 farms and 9.7 million cattle in the UK. Many public rights of way cross farmland, so while walking people come into contact with livestock, particularly cattle.

Within the various guidelines reviewed, advice of how to behave around cattle and avoid injury were found to vary, in particular concerning control of dogs.

Dr Westgarth added: “The countryside is a great place to exercise dogs, but it’s every owner’s duty to make sure that their dog is not a danger or nuisance to farm animals, wildlife or other people. Considering our findings, the best advice, if cattle approach, would be to let your dog off the lead, as then it can escape, and the cows are also likely to remove their focus from you.”  Science Daily  Original web page at Science Daily


You can teach an old dog new tricks, but younger dogs learn faster

The effect of aging on cognitive processes such as learning, memory and logical reasoning have so far been studied almost exclusively in people.

Using a series of touchscreen tests, Lisa Wallis and Friederike Range of the Messerli Research Institute at Vetmeduni Vienna have now studied these domains in pet dogs of varying ages. The study was conducted with 95 Border Collies ranging in age from five months to 13 years. The dogs regularly came to the Clever Dog Lab on the Vetmeduni Vienna campus accompanied by their owners to conduct the tests on a touch-sensitive monitor.

“Border Collies have a reputation for being fast learners. They were bred over generations for characteristics that are important in shepherding. In recent years they have become a popular breed of pet dog, probably because they are so easy to train. This is why we had access to enough test animals from this breed,” explains study director Friederike Range.

The dogs were divided into five age groups and tested in four tasks. These were designed to test three cognitive abilities: learning, logical reasoning and memory. Older dogs learn more slowly and exhibit lower cognitive flexibility

The tests revealed differences in cognitive ability depending on the age of the dogs. The first part required the animals to learn to correctly select four from a total of eight abstract pictures on a touchscreen. The dogs were shown two pictures on the screen at a time. One picture had a positive association — the dogs were rewarded with a food treat for touching this picture — while the second picture had a negative association — touching this picture did not result in a treat but in a time-out. The four “positive” pictures were presented in different combinations with the “negative” pictures.

“Older dogs required more trials than younger ones before they were able to solve the task correctly. The test also showed that older dogs are less flexible in their way of thinking than younger ones. As in people, older dogs find it more difficult to change old habits or what they have learned,” explains Lisa Wallis, the study’s first author.

After the Border Collies reached a learning criterion they were again shown two pictures on the touchscreen. This time, one of the pictures was new for the animals. The second one was familiar from the previous test where it had a negative association. The dogs should identify it as the “wrong” one. The novel picture would therefore be the “correct” one. Hence, the dogs had to choose through inference by exclusion.

“The older the dog, the better it performed, while younger dogs were unable to master this task. This is probably due to the fact that older dogs more stubbornly insist on what they have learned before and are less flexible than younger animals,” says Range.

Long-term memory for touchscreen stimuli is not affected by age: Six months after the first learning tests, the researchers repeated the touchscreen trials using the same eight abstract pictures as before in order to test the dog’s long-term memory skills. The test revealed no significant age differences. Nearly all dogs remembered the correct pictures as positive.

The results of this study provide measures associated with normal cognitive aging in Border collies, and thus could be used as a basis for breed comparisons as well as early recognition and treatment of certain cognitive deficits.  Science Daily  Original web page at Science Daily


* Dog domestication may have increased harmful genetic changes, biologists report

The domestication of dogs may have inadvertently caused harmful  genetic changes, a UCLA-led study suggests. Domesticating dogs from gray wolves more than 15,000 years ago involved artificial selection and inbreeding, but the effects of these processes on dog genomes have been little-studied.

UCLA researchers analyzed the complete genome sequences of 19 wolves; 25 wild dogs from 10 different countries; and 46 domesticated dogs from 34 different breeds. They found that domestication may have led to a rise in the number of harmful genetic changes in dogs, likely as a result of temporary reductions in population size known as bottlenecks.

“Population bottlenecks tied to domestication, rather than recent inbreeding, likely led to an increased frequency of deleterious genetic variations in dogs,” said Kirk Lohmueller, senior author of the research and assistant professor of ecology and evolutionary biology in the UCLA College.

“Our research suggests that such variants may have piggybacked onto positively selected regions, which were also enriched in disease-related genes,” Lohmueller said. “Thus, the use of small populations artificially bred for desired traits, such as smaller body size or coat color, may have led to an accumulation of harmful genetic variations in dogs.”

Such variations, Lohmueller said, could potentially lead to a number of different developmental disorders and other health risks.

Selective breeding programs, particularly those aimed at conserving rare and endangered species, may need to include and maintain large populations to minimize the inadvertent enrichment of harmful genetic changes, he said.

The research was published recently in the journal Proceedings of the National Academy of Sciences.  Science Daily  Original web page at Science Daily


Detection dogs help map out bear habitat in Greater Yellowstone

A recently released study from WCS (Wildlife Conservation Society) details a new method using “detection dogs,” genetic analysis, and scientific models to assess habitat suitability for bears in an area linking the Greater Yellowstone Ecosystem (GYE) to the northern U.S. Rockies.

The method, according to the authors, offers an effective, non-invasive approach to the collection of data that could play a vital role in the further recovery of grizzly bears during the coming decades.

“The use of detection dogs allowed us to quantify and map key areas of habitat for black bears in the Centennial Mountains located along the Idaho-Montana border west of Yellowstone National Park,” said Jon Beckmann, WCS Scientist and lead author of the study. “Black bears are a proxy species useful for predicting likely grizzly bear habitat. With recovery, a larger grizzly bear population needs room to roam and to reconnect with other populations. The Centennial Mountains region of the U.S. northern Rockies can provide room and safe linkages — critical to connecting the bear population in the GYE area to others further north and west.”

During the study, two Labrador retrievers and two German shepherds owned and trained by Working Dogs for Conservation, located 616 scat samples of black bears and 24 of grizzly bears (identified by DNA extraction and analysis) in the 2500 square kilometer (965 square mile) study area.

“Dogs excel at searching for multiple scents at once, even if one is far more common than the other,” according to Aimee Hurt, Working Dogs for Conservation co-founder. “In this case, the dogs easily alerted us to a multitude of black bear scat, while also readily locating the rare grizzly bear scat, resulting in a multitude of data points and a robust model.”

“We recognize that black bears do not always utilize the landscape in precisely the same manner as grizzly bears,” said Beckmann. “But given the paucity of grizzly bears in the study area — especially during the years of our study — our approach, data, and model have value to grizzly bear conservation and management. This is especially true given that black bears and grizzly bears in the GYE are known to utilize very similar habitats spatially, but at different times.”

Plugging the scat sample location data into their scientific model, the scientists examined the landscape with respect to habitat parameters, private lands, public land management and human activity in the area. Results of modeling provided insight into bear habitat use and resource selection patterns.

Among the findings it was determined that distance to roads matters; bears use habitat that is farther from roads, and when road density increased within 4 kilometers of a location bears used that habitat less. Bears also used a habitat less if it were high elevation, or privately owned. With this information land managers, land trusts, and others will be better informed to make bear habitat management and conservation decisions. This study may also inform human-bear conflict avoidance, and so help people and bears better co-exist.

“Using Detection Dogs and RSPF Models to Assess Habitat Suitability for Bears in Greater Yellowstone,” appears in the current edition of Western North American Naturalist.  Science Daily  Original web page at Science Daily


Plague-riddled prairie dogs a model for infectious disease spread

Every now and then, colonies of prairie dogs are wiped out by plague, an infectious disease most often associated with the Black Death of the 14th century.

Plague doesn’t usually kill people these days, but it’s alive and well among the millions of ground-dwelling rodents of Colorado and other western states, notably the black-tailed prairie dog. They’re resilient critters, though: following wholesale destruction of colonies, they seem to repopulate with a vengeance.

Colorado State University biologists say this sporadic ebb and flow of prairie dog plague is an ideal model for the study of rare infectious zoonotic disease — disease that can jump from wildlife to humans — like MERS (Middle East Respiratory Syndrome) and Ebola.

Plague, in all its terrible forms, is caused by the Yersinia Pestis bacterium, usually spread through flea bites. Last year in Colorado, there were a handful of human cases, including at least two deaths.

A multi-year, CSU-led study that involved trapping and testing thousands of prairie dogs across the Pawnee National Grassland, and tens of thousands of their plague-carrying fleas, was conducted by CSU biologists Daniel Salkeld and Michael Antolin, and is published Jan. 13 in BioScience.

Research scientist Salkeld and Antolin, professor and chair of biology in the College of Natural Sciences, assert that the swirl of ecological factors driving plague outbreaks in prairie dogs can lend key insights into the study of zoonotic diseases. Such diseases, among them Ebola, which swept through west Africa in 2014, are notoriously hard to study. Their outbursts are sporadic at best, making their spread trajectories elusive.

“Plague is deadly — it’s not like the common cold. It kills its host,” Salkeld said. “It affects different hosts, including rats, prairie dogs and grasshopper mice. It is reasonably rare to watch an outbreak, and doing so can give us insight into other rare diseases like Ebola.”

Throughout their analysis of plague in prairie dogs, they concluded that such diseases may “smolder” unnoticed in a population for years, rather than jump from species to species immediately before an outbreak. They also found that investigations occurring after outbreaks can be too shallow or yield false information about which host was chiefly responsible.

In other words, there’s no simple transmission model of diseases like Ebola and plague. Throughout their study, Salkeld and Antolin found that grasshopper mice and coyotes that scavenge plague-killed prairie dogs can speed transmission of the disease by spreading the disease-carrying fleas.

They also found that an outbreak in a prairie dog colony might go unnoticed for years, because the animals are dying underground. Furthermore, the mechanism that drives the spread of plague during the the smoldering, unnoticed period might be different than during a full-blown epidemic.

Ecological conditions come in bursts, too — for plague, a cool, wet season is best for the pathogen to proliferate. Prairie dogs are well adapted to surviving drought. “Prairie dogs spread like crazy during drought in Colorado,” Antolin said. “Without plague, they would probably spread faster during wet periods.”

The parallels with Ebola are without question, Antolin said. Ebola became a pandemic due to a combination of factors, including exposure of the virus in densely populated urban centers with little access to health care and sanitation. Similarly, the Black Death in medieval Europe spread due to things like concentrations of people living with animals; the pathogen was given a pathway to persist.

In the case of Ebola, they argue that the sampling of fruit bats after human outbreaks may have biased subsequent investigations toward bat-Ebola virus ecology, and other, possible host species may have been overlooked.

The researchers hope their study leads to better measures for modeling and predicting infectious disease transmission, but there are still open questions about the human-wildlife interface of disease. In future studies, Salkeld will continue to investigate this question with other human-wildlife diseases, including Lyme disease and Colorado tick fever.  Science Daily  Original web page at Science Daily


How dogs see your emotions: Dogs view facial expressions differently

A recent study from the University of Helsinki shows that the social gazing behavior of domestic dogs resembles that of humans: dogs view facial expressions systematically, preferring eyes. In addition, the facial expression alters their viewing behavior, especially in the face of threat. The study was recently published in the science journal PLOS ONE.

The study utilized eye gaze tracking to demonstrate how dogs view the emotional expressions of dog and human faces. Dogs looked first at the eye region and generally examined eyes longer than nose or mouth areas. Species-specific characteristics of certain expressions attracted their attention, for example the mouths of threatening dogs. However, dogs appeared to base their perception of facial expressions on the whole face.

Threatening faces evoked attentional bias, which may be based on an evolutionary adaptive mechanism: the sensitivity to detect and avoid threats represents a survival advantage. Interestingly, dogs’ viewing behavior was dependent on the depicted species: threatening conspecifics’ faces evoked longer looking but threatening human faces instead an avoidance response. Threatening signals carrying different biological validity are most likely processed via distinctive neurocognitive pathways.

“The tolerant behavior strategy of dogs toward humans may partially explain the results. Domestication may have equipped dogs with a sensitivity to detect the threat signals of humans and respond them with pronounced appeasement signals,” says researcher Sanni Somppi from the University of Helsinki.

This is the first evidence of emotion-related gaze patterns in non-primates. Already 150 years ago Charles Darwin proposed that the analogies in the form and function of human and non-human animal emotional expressions suggest shared evolutionary roots. Recent findings provide modern scientific support for Darwin’s old argument.

A total of 31 dogs of 13 different breeds attended the study. Prior the experiment the dogs were clicker-trained to stay still in front of a monitor without being commanded or restrained. Due to positive training approach, dogs were highly motivated to perform the task.

The study is part of the collaboration project of Faculties of Veterinary Medicine and Behavioural Science, University of Helsinki and Department of Neuroscience and Biomedical Engineering, Aalto University. Previously, the research group of professor Outi Vainio from the University of Helsinki has discovered that socially informative objects in images, as personally familiar faces and social interaction, attract dogs’ attention.  Science Daily  Original web page at Science Daily


Dogs and opossums positive for vaccinia virus during outbreak affecting cattle and humans

During a vaccinia virus (VACV) outbreak in São Paulo State, Brazil, blood samples were collected from cows, humans, other domestic animals, and wild mammals. Samples from 3 dogs and 3 opossums were positive for VACV by PCR. Results of gene sequencing yielded major questions regarding other mammalian species acting as reservoirs of VACV.

Since the first vaccinia virus (VACV) outbreak in Brazil in 1999, researchers have speculated on the origins and possible reservoirs of VACV. Wild and peridomestic rodents are known to be reservoirs of cowpox in Europe, but in Brazil, their involvement as VACV reservoirs is unclear. Although studies have reported experimental transmission of VACV between rodents and cows, this finding was not confirmed during outbreaks in Brazil.

The isolation and characterization of a VACV isolate in a peridomestic rodent has been described on a farm in Minas Gerais State, which raised questions about the role of rodents in VACV maintenance in Brazil. However, a recent serologic study on VACV reservoirs suggested that wild rodents might have a secondary role in VACV maintenance in São Paulo State.

Despite the absence of reports of clinical signs in dogs and other domestic or wild mammals during VACV outbreaks, in this report, we describe 3 dogs (Canis lupus familiaris) and 3 opossums (Didelphis albiventris) without clinical signs that were obtained during from a VACV outbreak. Blood samples from these animals were positive by PCR for VACV.  Emerging Infectious Diseases  Original web page at Emerging Infectious Diseases

Cartoons News

First puppies born by in vitro fertilization


First puppies born by in vitro fertilization
VetScite News, January 13, 2016


* Molecular processes for targeted dog cancer therapy investigated

Dogs get cancer, just like humans. Scientists at the University of Veterinary Medicine, Vienna are now exploring the molecular basis of cancer progression in canine cell lines. Modern cancer therapy has been revolutionized with the introduction of new drugs, so-called ‘targeted drugs’, but the basis for the application of these new agents in cancer therapy is a deep understanding of the molecular mechanisms of the disease, even with pets. Now a research team led by Sabine Macho-Maschler has investigated the activation of genetic regulatory mechanisms in canine cells and found both matches as well as differences compared to humans.

Almost every second dog above the age of ten years develops cancer. Modern tumor therapy combines surgery, radiation therapy and novel drug treatment options. While surgery and radiotherapy ensure adequate treatment for all animals at the University of Veterinary Medicine, Vienna, there is a growing gap in the treatment with modern therapeutics. The reason for this is that modern targeted agents are based on specific molecular genetics findings, which are not easy to transfer to dogs from humans or the preferred animal model in cancer research, the mouse. So to make modern cancer drugs also accessible to our four-legged friends requires comparative research into the molecular basis of cancer in dogs.

Our understanding of the molecular and cellular causes that are responsible for the development of cancer has grown strongly in recent years. This knowledge aids us in combating cancer cells with a growing number of new drugs. However, since cancer may manifest itself differently in each patient, an extensive molecular study of the existing mutations in cancer cells is an important prerequisite for successful therapy. This is because the targeted agents can only actually help when the cancer cells possess the corresponding molecular structures against which the drug is designed to act. The success of treatment with targeted drugs requires a molecular diagnosis, as basis for the so-called ‘personalized medicine’ in cancer research.

A research team at the Unit of Molecular Genetics have investigated an important process in the molecular genetics of cancer development in canine cell lines. These cell lines have long been used by researchers to analyze pathological processes and now were analyzed for changes in the expression of several RNA-species using next generation sequencing. “Cancer researchers have been working for many years on the transition of epithelial tumor cells into the more aggressive mesenchymal state. Important gene switches could be identified in this process with potential for use as therapeutic targets: these gene products could be targeted with novel therapeutics,” explained Macho-Maschler, who headed the now published study.

Research on epithelial-mesenchymal transition (EMT) has so far mainly focused on cells of mice and humans and showed how certain signaling pathways cooperate to allow cancer cells metastasis. Metastases are formed when the originally sedentary cancer cells obtain certain properties, which allow them to migrate into another organ and to form a new tumor there. “In the majority of cases it is the metastases that cost the patient’s live, as the original tumor can often be well controlled by radiation and surgery,” emphasized Mathias Müller, head of the Institute for Animal Breeding and Genetics. “We are interested in what is going on at the molecular level during metastasis, as it is likely that we can use this knowledge for the successful treatment of metastases.”

The molecular analysis of EMT is considered by researchers as a model for the acquisition of the ability to metastasize. The TGF-beta pathway has for a long time been recognized as a central switch in this process. Macho-Maschler expressed her satisfaction with the many similarities seen in the comparative analysis of results for canine, human and mouse cells. “TGF-beta, for example, also plays an important role in dogs, but there are also interesting variations,” reports Macho-Maschler. Her recent BMC Genomics publication is filled with long lists of RNAs that are regulated during EMT. These findings should serve as a basis for further analysis. Macho-Maschler is skeptical as to whether their research can improve the treatment of dogs with cancer in the near future. “Our newly published results are like a catalogue, perhaps an important requirement for new approaches and ideas. Ultimately, we do not even know whether many of the new drugs actually act in canine cells. There are, for example, targeted drugs which act only in humans but not in mice” says Macho-Maschler to dampen unrealistic expectations. In humans, a much more comprehensive catalogue was completed this year; “The Cancer Genome Atlas” makes available to researchers the essential information contained within 11,000 genetically analyzed patient samples ( It is an important resource, which enables researchers quickly and reliably to check the frequency of certain genetic changes in a cancer. The catalogue published by Macho-Maschler is naturally not comparable with the TCGA, but it is a first important step in the same direction for canine cancer.  Science Daily  Original web page at Science Daily


Dogs thwart effort to eradicate Guinea worm

Most cases of Guinea-worm disease in Chad have occurred in communities based along the Chari River. A decades-long push to make Guinea-worm disease the first parasitic infection to be wiped out is close to victory. But a mysterious epidemic of the parasite in dogs threatens to foil the eradication effort.

The Carter Center in Atlanta, Georgia, is leading the global campaign to eradicate Guinea worm. Next week, it will announce that case numbers for the excruciatingly painful infection are at a record low, with approximately 25 cases reported in 2015 in just 4 countries: Chad, Ethiopia, Mali and South Sudan. But infections in dogs are soaring in Chad, where officials will meet at the end of January to grapple with the canine epidemic. The central African nation recorded more than 450 cases of Guinea worm in domestic dogs last year — an all-time high.

Researchers and officials strongly suspect that dogs are spreading the infection to humans; now the race is on to understand how this might happen, as well as how dogs acquire the infection in the first place. The World Health Organization is unlikely to declare Guinea worm eradicated until the parasite has stopped spreading in dogs, says Molyneaux, who is part of the commission that will make that decision.

In 1986, when the Carter Centre joined the Guinea-worm eradication campaign, there were an estimated 3.5 million infections annually, mostly due to poor sanitation and lack of access to clean water.

When people drink unfiltered water, they can swallow microscopic freshwater crustaceans called copepods, which Guinea-worm larvae infect. The copepods die, releasing the larvae, which mature and mate in the human intestine. Male worms die after mating, but adult females — approximately 80 centi­metres in length — survive and slowly migrate out of the gut. About a year after infection, they burrow through their host’s skin, usually around the legs and feet, sometimes taking weeks to fully escape. To cope with the searing pain, many people bathe in rivers and lakes, contaminating the water with the next generation of larvae. Although rarely fatal, Guinea worm can debilitate people for months and keep children out of school.

There is no vaccine against the parasite and no effective treatment, so eradication efforts have focused on providing clean water and changing people’s behaviour, says Donald Hopkins, a special adviser at the Carter Center who is leading its Guinea-worm eradication efforts. People in areas in which the parasite was once rife have learnt to filter their water using cloths and to avoid re-contaminating water supplies. Even the most out-of-the-way villages now quickly contain cases and report them to health officials.

Chad was on the cusp of being declared free of Guinea worm in the late 2000s: no case had been recorded in the previous decade. But starting in April 2010, increased surveillance turned up a handful of human infections, and around 60 cases have been recorded since then.

The cases are unusually sporadic and isolated from one another, says Mark Eberhard, a parasitologist who consults on Guinea-worm eradication for the Carter Center. More typically, cases occur in clusters and recur in the same village year after year. “There was no increase or explosion of cases as one would expect,” he says.

Shortly after these observations, officials began to hear rumours of Guinea-worm-infected dogs in Chad. Researchers have known for decades that dogs, leopards and other mammals occasionally acquire Guinea-worm-like infections, but they assumed that these cases stemmed from distinct species of Dracunculus, the nematode worm that causes the disease, or were rare examples of infections that had somehow spilt over from an outbreak in humans.

But in Chad, researchers now think that dogs are spreading the worms to humans — not the other way around. Between January and October 2015, officials recorded 459 canine infections from 150 villages in the central African nation — an unprecedented volume. And genome sequencing has confirmed that dogs in Chad are infected by the same nematode worms (Dracunculus medinensis) that plague humans (M. L. Eberhard et al. Am. J. Trop. Med. Hyg. 90, 61–70; 2014).

To better understand the situation, a team led by James Cotton and Caroline Durrant, genome scientists at the Wellcome Trust Sanger Institute in Hinxton, UK, is now sequencing the genomes of more Guinea worms collected from dogs and humans in Chad to confirm that dogs are indeed transmitting the disease to people. And Eberhard, who is convinced that this is the case, is trying to determine how dogs become infected in the first place. They are unlikely to contract the worms from drinking water, he says, because dogs tend to scare away copepods when they lap. Most of Chad’s cases have occurred among fishing communities along the Chari River, and Eberhard suspects that dogs are eating the entrails of gutted, copepod-eating fish. Dogs then pass the worms to humans by reintroducing the larvae into water.

Researchers, including Eberhard, are testing aspects of this hypothesis in ferrets, a common animal model in disease research, but eradication officials in Chad are not waiting for the results before taking action. Since February 2015, they have offered the equivalent of US$20 to people who report Guinea-worm cases in dogs and tie up the animals to prevent them from contaminating water sources. They are also encouraging villagers to bury fish entrails to keep dogs from eating them. And a trial is ongoing to test whether a drug used to treat heartworm — a roundworm parasite common in dogs — has any effect on Guinea worm. Because of Guinea worm’s one-year incubation time, it should be clear before the end of 2016 whether these interventions have worked.

Older residents from villages along the Chari River say that their fishing practices have not changed, according to Hopkins, and they cannot recall dogs becoming infected with Guinea worm in the past. But Molyneaux says that the dearth of humans transmitting the disease could explain the parasite’s jump to dogs. “If you were Guinea worm and there were only 100 of you left in the world,” he says, “what would you do? You’d get the hell out of the host that’s being targeted and move to something else.”

Nature 529, 10–11 (07 January 2016) doi:10.1038/529010a Nature  Original web page at Nature


* First puppies born by in vitro fertilization

For the first time, a litter of puppies was born by in vitro fertilization, thanks to work by Cornell University researchers. The breakthrough, described in a study to be published online Dec. 9 in the journal Public Library of Science ONE, opens the door for conserving endangered canid species, using gene-editing technologies to eradicate heritable diseases in dogs and for study of genetic diseases. Canines share more than 350 similar heritable disorders and traits with humans, almost twice the number as any other species.

Nineteen embryos were transferred to the host female dog, who gave birth to seven healthy puppies, two from a beagle mother and a cocker spaniel father, and five from two pairings of beagle fathers and mothers.

“Since the mid-1970s, people have been trying to do this in a dog and have been unsuccessful,” said Alex Travis, associate professor of reproductive biology in the Baker Institute for Animal Health in Cornell’s College of Veterinary Medicine.

Jennifer Nagashima, a graduate student in Travis’ lab and the first to enroll in the Joint Graduate Training Program between the Smithsonian Conservation Biology Institute and Cornell’s Atkinson Center for a Sustainable Future, is the paper’s first author.

For successful in vitro fertilization, researchers must fertilize a mature egg with a sperm in a lab, to produce an embryo. They must then return the embryo into a host female at the right time in her reproductive cycle.

The first challenge was to collect mature eggs from the female oviduct. The researchers first tried to use eggs that were in the same stage of cell maturation as other animals, but since dogs’ reproductive cycles differ from other mammals, those eggs failed to fertilize. Through experimentation, Nagashima and colleagues found if they left the egg in the oviduct one more day, the eggs reached a stage where fertilization was greatly improved.

The second challenge was that the female tract prepares sperm for fertilization, requiring researchers to simulate those conditions in the lab. Nagashima and Skylar Sylveste, found that by adding magnesium to the cell culture, it properly prepared the sperm. “We made those two changes, and now we achieve success in fertilization rates at 80 to 90 percent,” Travis said.

The final challenge for the researchers was freezing the embryos. Travis and colleagues delivered Klondike, the first puppy born from a frozen embryo in the Western Hemisphere in 2013. Freezing the embryos allowed the researchers to insert them into the recipient’s oviducts (called Fallopian tubes in humans) at the right time in her reproductive cycle, which occurs only once or twice a year.

The findings have wide implications for wildlife conservation because, Travis said, “We can freeze and bank sperm, and use it for artificial insemination. We can also freeze oocytes, but in the absence of in vitro fertilization, we couldn’t use them. Now we can use this technique to conserve the genetics of endangered species.”

In vitro fertilization allows conservationists to store semen and eggs and bring their genes back into the gene pool in captive populations. In addition to endangered species, this can also be used to preserve rare breeds of show and working dogs.

With new genome editing techniques, researchers may one day remove genetic diseases and traits in an embryo, ridding dogs of heritable diseases. While selecting for desired traits, inbreeding has also led to detrimental genetic baggage. Different breeds are predisposed to different diseases; Golden retrievers are likely to develop lymphoma, while Dalmatians carry a gene that predisposes them to blockage with urinary stones.

“With a combination of gene editing techniques and IVF, we can potentially prevent genetic disease before it starts,” Travis said. Finally, since dogs and humans share so many diseases, dogs now offer a “powerful tool for understanding the genetic basis of diseases,” Travis said.  Science Daily  Original web page at Science Daily


Precise method underlies sloppy madness of dog slurping

Stories about lap dogs are everywhere, but researchers at the Virginia Tech College of Engineering can tell the story of dog lapping.

Using photography and laboratory simulations, researchers studied how dogs raise fluids into their mouths to drink. They discovered that sloppy-looking actions at the dog bowl are in fact high-speed, precisely timed movements that optimize a dogs’ ability to acquire fluids. Their discovery appears today in the Proceedings of the National Academy of Sciences.

Researchers also compared what they learned about how dogs drink with what they knew from previous studies of cats. The scientists discovered that even though feline and canine mouths structurally are similar, their approaches to drinking are as different as — cats and dogs.

“We know cats and dogs are quite different in terms of behavior and character,” said Sunghwan “Sunny” Jung, an associate professor of biomedical engineering and mechanics. “But before we did fundamental studies of how these animals drink fluids, our guess was dogs and cats drink about the same way. Instead we found out that dogs drink quite differently than cats.”

Dogs and cats are biting animals and neither have full cheeks. But without cheeks, they can’t create suction to drink — as people, horses, and elephants do. Instead they use their tongues to quickly raise water upward through a process involving inertia.

Both animals move their tongues too quickly to completely observe by the naked eye. But dogs accelerate their tongues at a much faster rate than cats, plunging them into the water and curling them downward toward their lower jaws, not their noses.

They quickly retract their tongues and a column of water forms and rises into their mouths, but they also curl the underside of their tongues to bring a tiny ladle of water upward.

Dogs precisely bite down to capture the water. In an instant they reopen their mouths and immerse their tongues back into the water.

Cats, on the other hand, lightly touch the surface of the water with their tongues, usually never fully immersing them, according to previous imaging by Jung and other researchers. When their tongues rise into their mouths, liquid adheres to the upper side, forming an elegant water column.

When dogs accelerate their tongues upwards, the latest research reveals a water column rising, but some water remains in the ladle of the tongue and is tossed to either side of the dog’s mouth.

Although dogs do not use their tongues to actively scoop water into their mouths, it is possible that the scooped liquid has some positive effect on the water column dynamics below the tongue, the researchers said.

“Dog drinking is more acceleration driven using unsteady inertia to draw water upward in a column, where cats employ steady inertia,” Jung said.

In all, 19 dogs of various sizes and breeds were volunteered for filming by their owners. Thirteen of the dogs were filmed outdoors at their owners’ residences in the Blacksburg, Virginia, area. The remaining six were filmed at the Virginia Tech campus.

“This was a basic science study to answer a question very little was known about — what are the fundamental mechanics of how dogs drink?” said Sean Gart, a graduate student in biomedical engineering and mechanics who filmed the dogs. “Cats tend be viewed as neater, dogs are messier, but dogs really have to accelerate their tongues to exploit the fluid dynamics of the water column.

The researchers measured tongue motion, recorded water volumes, and generally measured lapping in the dogs. They used the results to generate a physical model in the laboratory of the tongue’s interaction with the air-fluid interface, according to Jake Socha, an associate professor of biomedical engineering and mechanics at Virginia Tech.

Pavlos Vlachos, a professor of mechanical engineering at Purdue University, also participated in the study.The research, supported by the National Science Foundation, is an accomplishment of the Bio-Inspired Fluid Lab of the Virginia Tech College of Engineering. The lab seeks to take cues from living systems to make practical applications that exploit the natural movement of fluids.  Science Daily  Original web page at Science Daily


Dogs give friends food

Compared to the rest of the animal kingdom, the human capacity for cooperation is something quite special. Cooperating with one another requires a certain amount of prosocial behaviour. This means helping others without any direct personal benefit.

Prosociality has already been demonstrated in animals that are very closely related with humans, i.e. primates. In other animals, the phenomenon has so far only been studied experimentally in rats and jackdaws. One study found prosocial behaviour in dogs toward humans. According to Friederike Range of the Messerli Research Institute, however, it remains questionable whether the dogs were merely reacting to the communication from the humans and were being “obedient” or if they were truly exhibiting prosocial behaviour.

“Dogs and their nearest relatives, the wolves, exhibit social and cooperative behaviour, so there are grounds to assume that these animals also behave prosocially toward conspecifics. Additionally, over thousands of years of domestication, dogs were selected for special social skills,” explains study director Range. For this reason, Range and her colleagues Mylene Quervel-Chaumette, Rachel Dale and Sarah Marshall-Pescini studied 16 dogs to test their readiness to benefit familiar versus unfamiliar partners.

The researchers studied the prosocial behaviour of the animals using a bar-pulling task in which the dogs had to pull trays and decide whether a second dog would receive a treat or not. In the test, the donor dogs used their mouths to pull a string to bring a tray toward a second dog. They could choose either an empty tray or a tray containing a treat on the partner’s side.

Dogs donate to familiar partners more often than to unfamiliar ones.

Whether the donor dogs knew the recipient made a difference. Donor dogs pulled the giving tray more often for familiar dogs than for unfamiliar ones. “Dogs truly behave prosocially toward other dogs. That had never been experimentally demonstrated before. What we also found was that the degree of familiarity among the dogs further influenced this behaviour. Prosocial behaviour was exhibited less frequently toward unfamiliar dogs than toward familiar ones.

In the bar-pulling task, the donor dogs decided whether another dog would receive a treat or not. The donor dog itself did not get the treat. The only purpose of the task was to benefit the other dog. By conducting several control tests, the researchers excluded the possibility that the dogs were simply pulling the trays for the fun of it. Donor dogs were reserved in pulling the tray when an unfamiliar dog was in the next enclosure.

At the end of each test run, the researchers conducted another test to show that the donor dogs knew what pulling the tray meant. They allowed the donor dogs to pull on a tray to give themselves a treat, and all dogs did just that. “This control excludes the possibility that the dogs did not pull on the tray out of fear of the unfamiliar dogs. Given the same situation, the dogs gladly gave themselves a treat,” says Range.

“We were also able to disprove the argument that the dogs pulled the string less frequently because they were distracted by the unfamiliar partner during the test. Only rarely did a donor dog interact with the unfamiliar dog,” Range explains.  Science Daily  Original web page at Science Daily


* Puppy bred to have muscular dystrophy saved by surprise mutation

Ringo, a golden retriever born in 2003 in a Brazilian kennel, was never expected to live long. Researchers bred him and his littermates to inherit a gene mutation that causes severe muscular dystrophy. They hoped that the puppies would provide insight into Duchenne muscular dystrophy (DMD), an untreatable and ultimately fatal human disease caused by inactivation of the same gene.

But Ringo’s muscles didn’t waste away like his littermates’, and researchers have now determined why: he was born with another mutation that seems to have protected him from the disease, according to a paper published in Cell. Scientists hope that by studying Ringo’s mutation — which has never before been linked to muscular dystrophy — they can find new treatments for the disease.

As many as 1 in 3,500 boys inherit mutations that produce a broken version of a protein called dystrophin, causing DMD. (The disease appears in boys because the dystrophin gene sits on the X chromosome, so girls must inherit two copies of the mutated gene to develop DMD.) The protein helps to hold muscle fibres together, and its absence disrupts the regenerative cycle that rebuilds muscle tissue. Eventually, fat and connective tissue replace muscle, and people with DMD often become reliant on a wheelchair before their teens. Few survive past their thirties.

Some golden retriever females carry dystrophin mutations that cause a similar disease when passed onto male puppies. Dog breeders can prevent this through genetic screening. But Mayana Zatz, a geneticist at the University of São Paulo in Brazil, and her colleagues set out to breed puppies with the mutation to model the human disease.

DNA testing confirmed that Ringo had inherited the dystrophin mutation, but he showed none of the severe symptoms. Ringo’s case flummoxed Zatz and her team, so she decided to follow his life closely in her laboratory’s kennel. “We treat the dogs here like children,” Zatz says. “They are very well kept, they have a place to run, they have sun, and air conditioning when it’s hot.”

Ringo proved something of a troublemaker. “When people would leave the door open he would run and mate,” Zatz says. In total, Ringo sired 49 puppies with four different females — “from natural intercourse”, she and colleagues note in one paper. One of his puppies, Suflair, also never developed full muscular dystrophy, despite inheriting a faulty dystrophin gene.

“These were two very unusual dogs, the father and the son, so we decided to map what gene might be the modifier,” says Louis Kunkel, a geneticist at Boston Children’s Hospital in Massachusetts, who first identified the gene and protein responsible for DMD in the 1980s. Kunkel became involved with Ringo and Suflair when a former graduate student in Zatz’s lab, Natassia Viera, did a postdoc in his lab.

The team compared the genomes of Ringo and Suflair with those of other golden retrievers with muscular dystrophy and identified a mutation in a development gene, Jagged, that distinguished the father and son from 31 severely affected dogs in the same colony. The muscles of Ringo and his son harboured higher levels of the Jagged1 protein compared with affected dogs. When the researchers mimicked this trait in zebrafish lacking dystrophin, it also protected the fish from muscle tearing and other symptoms of muscular dystrophy.

Kunkel says that the team does not yet know how higher levels of Jagged1 protect the dogs from muscular dystrophy. The protein is a player in a pathway with a role in many aspects of biology, including muscle development and regeneration. Perhaps, says Kunkel, Ringo and Suflair’s Jagged1 mutation compensates for the muscle regeneration problems caused by a lack of dystrophin. They are now looking for drugs that produce higher levels of Jagged1 in mice and zebrafish. But Kunkel cautions that it will be difficult to mimic the dogs’ exact biology with a drug.

Elizabeth McNally, a geneticist at Northwestern University Feinberg School of Medicine in Chicago, Illinois, thinks that mutations that counteract muscular dystrophy could point to new treatments — not only for DMD, but also for other causes of muscle atrophy including old age. “I love that it came out of the dog model,” she says.

Ringo died last year aged 11, within the normal lifespan for a golden retriever. Nearly 10 years old, Suflair is now showing his age too. “Suflair can walk but he can’t jump anymore,” Zatz says. “But he’s an old dog.”

Nature doi:10.1038/nature.2015.18784  Nature  Original web page at Nature


* Gene therapy treats all muscles in the body in muscular dystrophy dogs

Muscular dystrophy, which affects approximately 250,000 people in the US, occurs when damaged muscle tissue is replaced with fibrous, fatty or bony tissue and loses function. For years, scientists have searched for a way to successfully treat the most common form of the disease, Duchenne Muscular Dystrophy (DMD), which primarily affects boys. Now, a team of researchers has successfully treated dogs with DMD and say that human clinical trials are being planned in the next few years.

Muscular dystrophy, which affects approximately 250,000 people in the U.S., occurs when damaged muscle tissue is replaced with fibrous, fatty or bony tissue and loses function. For years, scientists have searched for a way to successfully treat the most common form of the disease, Duchenne Muscular Dystrophy (DMD), which primarily affects boys. Now, a team of University of Missouri researchers have successfully treated dogs with DMD and say that human clinical trials are being planned in the next few years.

“This is the most common muscle disease in boys, and there is currently no effective therapy,” said Dongsheng Duan, the study leader and the Margaret Proctor Mulligan Professor in Medical Research at the MU School of Medicine. “This discovery took our research team more than 10 years, but we believe we are on the cusp of having a treatment for the disease.”

Patients with Duchenne muscular dystrophy have a gene mutation that disrupts the production of a protein known as “dystrophin.” Absence of dystrophin starts a chain reaction that eventually leads to muscle cell degeneration and death. Affected boys lose their ability to walk and breathe as they get older. This places significant limitations on individuals afflicted with the disease. Dystrophin also is one of the largest genes in the human body.

“Due to its size, it is impossible to deliver the entire gene with a gene therapy vector, which is the vehicle that carries the therapeutic gene to the correct site in the body,” Duan said. “Through previous research, we were able to develop a miniature version of this gene called a microgene. This minimized dystrophin protected all muscles in the body of diseased mice.”

However, it took the team more than 10 years to develop a strategy that can safely send the micro-dystrophin to every muscle in a dog that is afflicted by the disease. The dog has a body size similar to that of an affected boy. Success in the dog will set the foundation for human tests.

In this latest study, the MU team demonstrated for the first time that a common virus can deliver the microgene to all muscles in the body of a diseased dog. The dogs were injected with the virus when they were two to three months old and just starting to show signs of DMD. The dogs are now six to seven months old and continue to develop normally.

“The virus we are using is one of the most common viruses; it is also a virus that produces no symptoms in the human body, making this a safe way to spread the dystrophin gene throughout the body,” Duan said. “These dogs develop DMD naturally in a similar manner as humans. It’s important to treat DMD early before the disease does a lot of damage as this therapy has the greatest impact at the early stages in life.”  Original web page at   Science Daily


* Study stops vision loss in late-stage canine X-linked retinitis pigmentosa

Three years ago, a team from the University of Pennsylvania announced that they had cured X-linked retinitis pigmentosa, a blinding retinal disease, in dogs. Now they’ve shown that they can cure the canine disease over the long term, even when the treatment is given after half or more of the affected photoreceptor cells have been destroyed

Because the disease affects humans in almost the same fashion as it does dogs, the results suggest that this treatment could be effective and lasting in humans and could set the stage for safety studies that precede a human clinical trial.

“The 2012 study showed that gene therapy was effective if used as a preventive treatment or if you intervene right after the onset of cell death,” said William A. Beltran, co-lead author and associate professor of ophthalmology at Penn’s School of Veterinary Medicine. “That was obviously very encouraging. But now we’ve gone further, showing that the treatment is long-lasting and effective even when started at mid- and late-stage disease.”

“This happens to be a very severe disease with very early onset in the first two decades of life in humans,” said Artur V. Cideciyan, co-lead author and research professor of ophthalmology in the Scheie Eye Institute at Penn’s Perelman School of Medicine. “Because the progression of disease in dogs matches up with the progression in humans, this gives us a lot of confidence about translating these results to eventually treat humans.”

The work involved a close collaboration between Beltran and Cideciyan as well as Samuel G. Jacobson, professor of ophthalmology at Scheie, and Gustavo D. Aguirre, the paper’s senior author and professor of medical genetics and ophthalmology at Penn Vet. The Penn researchers have also long partnered with University of Florida scientists led by William Hauswirth, Rybaczki-Bullard Professor of Ophthalmology in the College of Medicine. Their work appears in Proceedings of the National Academy of Sciences.

X-linked retinitis pigmentosa, or XLRP, arises primarily from mutations in the RPGR gene, leading to progressive vision loss starting at a young age. Because it is an X chromosome-linked recessive disease, it overwhelmingly affects boys and men. It is one of the most common forms of inherited retinal disease.

Though rigorously studied, little is understood about the function of RPGR. It is believed to play a role in the function of the connecting cilium, a structure that is present in both rod and cone cells, the photoreceptor cells involved in dim-light and bright-light vision, respectively.

In XLRP, these photoreceptor cells progressively degenerate and die. To counter this effect, the Penn group’s earlier gene therapy work used a viral vector to deliver a normal copy of RPGR specifically to rods and cones using a subretinal injection.

In the new publication, the team reports that the therapy, which occurred when dogs were 5 weeks old, successfully stopped photoreceptor cell loss and maintained vision in dogs for more than three years of study.

This study also went further, using the same viral vector and same approach, except this time beginning the gene therapy intervention at two later time points: At 12 weeks of age, which the researchers term “mid-stage disease,” when approximately 40 percent of the eye’s photoreceptor cells have already died, or at 26 weeks of age, “late-stage disease,” when about 50 to 60 percent of the rods and cones were lost.

The team had concerns about treating at these later stages, both that the retina might not properly reattach following the therapeutic subretinal injection and that there could be toxicity from the viral vector due to the greater extent of photoreceptor cell degeneration. They saw no indications of either being a problem in their follow-up.

“We have spent a lot of time working to make sure the therapeutic gene is tightly regulated in terms of when and where it is expressed,” said Aguirre. “And, thankfully, we have seen that this therapy appears to be well tolerated in the retina.”

Instead, what they saw, using non-invasive tests used in human medicine, including electroretinography and optical coherence tomography imaging, was a remarkable and lasting halt in the degeneration of photoreceptor cells in the treated region of the retina. Dogs treated at these later stages of disease even had some of the structural abnormalities in the rods and cones reversed. And these findings translated to improved performance on visual behavior tests, a Y maze that tested whether the dogs could detect a dim light and an obstacle course that assessed their visual navigational skills. The dogs’ performances endured for at least two and a half years after treatment, the latest time point examined, in the late-stage group.

“What the dog studies show, especially those that are treated at a later stage, is that you can treat a relatively small region — 20 percent or less of the retinal surface, where you already had 50 percent of photoreceptor cells that died before treatment — and still see not only an electrophysiological improvement and rescue but an actual rescue of visual behavior,” Beltran said.

“Based on my experience developing gene therapies in animal models for many other inherited retinal diseases,” said the University of Florida’s Hauswirth, “I believe this report describes perhaps the strongest case yet for eventual successful therapy in humans for XLRP.”

As in their earlier work, the researchers showed that the function of both rods and cones was rescued and that these photoreceptor cells were properly connected to the neurons that transmit visual signals to the brain.

“Because this is a photoreceptor disease that affects both rods and cones, or night and day vision cells, to show that both were rescued was very wonderful to see,” Cideciyan said

“I worry a lot about my patients who have lost photoreceptor cells and possibly have abnormal connectivity and structure in their retina, whether gene therapy would still work for them at later stages of disease,” Jacobson said. “What we showed here is that the therapy resulted in downstream neurons that were robust and connected, which is exceptionally important for eventual human treatment.”

To move the work into the realm of human treatment, the researchers are examining patients to determine where in the retina may be a suitable place for injection and what patients might qualify for an eventual clinical trial. They are also studying the other genetic “partners” that function along with RPGR in the connecting cilium to see if there could be additional targets for therapy.  Science Daily  Original web page at Science Daily


* Hypoallergenic dogs don’t have lower household allergen levels than other dogs, study finds

Contrary to popular belief, so-called hypoallergenic dogs do not have lower household allergen levels than other dogs.

That’s the conclusion of a study by Henry Ford Hospital researchers who sought to evaluate whether hypoallergenic dogs have a lower dog allergen in the home than other dogs. Hypoallergenic dogs are believed to produce less dander and saliva and shed less fur.

The findings are to be published online this month in the American Journal of Rhinology and Allergy.

“We found no scientific basis to the claim hypoallergenic dogs have less allergen,” says Christine Cole Johnson, Ph.D., MPH, chair of Henry Ford’s Department of Public Health Sciences and senior author of the study.

“Based on previous allergy studies conducted here at Henry Ford, exposure to a dog early in life provides protection against dog allergy development. But the idea that you can buy a certain breed of dog and think it will cause less allergy problems for a person already dog-allergic is not borne out by our study.

This is believed to be the first time researchers measured environmental allergen associated with hypoallergenic dogs. Previous studies analyzed hair samples from only a handful of dogs in a small number of breeds

Henry Ford researchers analyzed dust samples collected from 173 homes one month after a newborn was brought home. The dust samples were collected from the carpet or floor in the baby’s bedroom and analyzed for the dog allergen Can f 1. Only homes with one dog were involved in the study. Sixty dog breeds were involved in the study, 11 of which are considered hypoallergenic dogs

Based on public web site claims of hypoallergenic breeds, dogs were classified as hypoallergenic using one of four “schemes” based on their breed for comparing allergen levels. Scheme A compared purebred hypoallergenic dogs to purebred non-hypoallergenic dogs; Scheme B compared purebred and mixed breed dogs with at least one hypoallergenic parent to purebred non-hypoallergenic dogs; Scheme C compared purebred and mixed breed dogs with at least one hypoallergenic parent to purebred and mixed breed dogs with no known hypoallergenic component; Scheme D compared only purebred dogs identified as hypoallergenic by the American Kennel Club to all other dogs.

Researchers found that the four schemes yielded no significant differences in allergen levels between hypoallergenic dogs and non-hypoallergenic dogs. In homes where the dog was not allowed in the baby’s bedroom, the allergen level for hypoallergenic dogs was slightly higher compared to allergen levels of non-hypoallergenic dogs.

While researchers acknowledged limitations in their study — the amount of time the dog spent in the baby’s bedroom was not recorded and the size of its sample did not allow looking at specific breeds — they say parents should not rely on dog breeds classified as hypoallergenic.  Science Daily  Original web page at Science Daily


Citizen scientists contribute to dog research

Five hundred citizen scientists around the world have contributed data to a study of what goes on inside the minds of their dogs. The research, appearing Sept. 16 in PLoS ONE, analyzes data collected by 500 dog owners who played the same games at home that researchers use in the laboratory to find out about a dog’s cognitive skills and problem-solving. On five of the seven tests analyzed, citizen science data corresponded closely to what had been produced by labs at Duke University and elsewhere.

For example, in one of the game-like tests, dogs were found to rely more on their memory than their sense of smell to find a hidden treat. The dogs watched as their owner hid food under one of two cups. Then while the dog’s vision was obscured, the owner switched the food to the other cup. If dogs could smell the food, they should have been able to choose the correct cup, but owners found that most dogs went to where they last saw the food.

The data were collected through a website called that was developed by Brian Hare, an associate professor of evolutionary anthropology at Duke who studies primate and dog cognition. Hare is also the founder of the Canine Cognition Center at Duke, which has a network of 1,000 dog owners who can bring their pets into the lab to participate in research. “They’re just games,” Hare said. “The owners love playing them and the dogs love playing them. I realized more people could play them if they were online.”

More than 17,000 dog owners from downtown Durham to Finland have signed up through Dognition and are sharing their data with the researchers. “The data these dog owners are producing is quality data,” said Evan MacLean, a senior research scientist at Duke and co-director of the Canine Cognition Center. “It matches the results we see coming out of the top research groups all over the world.”

According to MacLean, the memory-over-smell result has been replicated in seven different research groups and more than a dozen different studies. “Most people think dogs use their sense of smell for everything,” MacLean said. “But actually dogs use a whole range of senses when solving problems.”

Analysis of the unusually large dataset created by Dognition has also found that all dogs have a unique set of cognitive skills that they use to navigate the world around them. Some dogs were found to be good communicators, some had better memories and others were better at taking their owner’s perspective.

“Most people think of intelligence as glass that is more or less full,” Hare said. “But intelligence is more like ice cream. Everybody has different flavors. Being good at one thing doesn’t mean you will be good at everything else.” Hare said these kinds of findings are only possible with the big data sets that citizen scientists are able to generate. “‘So much is possible when you have this much data,” Hare said. “I’m looking forward to dog owners answering all the big questions that have puzzled scientists for decades.   Science Daily  Original web page at Science Daily


* Genetic mutations linked to a form of blindness

Achromatopsia is a rare, inherited vision disorder that affects the eye’s cone cells, resulting in problems with daytime vision, clarity and color perception. It often strikes people early in life, and currently there is no cure for the condition. One of the most promising avenues for developing a cure, however, is through gene therapy, and to create those therapies requires animal models of disease that closely replicate the human condition.

In a new study, a collaboration between University of Pennsylvania and Temple University scientists has identified two naturally occurring genetic mutations in dogs that result in achromatopsia. Having identified the mutations responsible, they used structural modeling and molecular dynamics on the Titan supercomputer at Oak Ridge National Laboratory and the Stampede supercomputer at the Texas Advanced Computing Center to simulate how the mutations would impact the resulting protein, showing that the mutations destabilized a molecular channel essential to light signal transduction.

The findings provide new insights into the molecular cause of this form of blindness and also present new opportunities for conducting preclinical assessments of curative gene therapy for achromatopsia in both dogs and humans.

“Our work in the dogs, in vitro and in silico shows us the consequences of these mutations in disrupting the function of these crucial channels,” said Karina Guziewicz, senior author on the study and a senior research investigator at Penn’s School of Veterinary Medicine. “Everything we found suggests that gene therapy will be the best approach to treating this disease, and we are looking forward to taking that next step.”

The research began with a German shepherd that was brought to Penn Vet’s Ryan Hospital. The owners were worried about its vision. “This dog displayed a classical loss of cone vision; it could not see well in daylight but had no problem in dim light conditions,” said Aguirre, professor of medical genetics and ophthalmology at Penn Vet.

The Penn Vet researchers wanted to identify the genetic cause, but the dog had none of the “usual suspects,” the known gene mutations responsible for achromatopsia in dogs. To find the new mutation, the scientists looked at five key genes that play a role in phototransduction, or the process by which light signals are transmitted through the eye to the brain.

They found what they were looking for on the CNGA3 gene, which encodes a cyclic nucleotide channel and plays a key role in transducing visual signals. The change was a “missense” mutation, meaning that the mutation results in the production of a different amino acid. Meanwhile, they heard from colleague Dixon that he had examined Labrador retrievers with similar symptoms. When the Penn team performed the same genetic analysis, they found a different mutation on the same part of the same gene where the shepherd’s mutation was found. Neither mutation had ever been characterized previously in dogs. “The next step was to take this further and look at the consequences of these particular mutations,” Guziewicz said.

The group had the advantage of using the Titan and Stampede supercomputers, which can simulate models of the atomic structure of proteins and thereby elucidate how the protein might function. That work revealed that both mutations disrupted the function of the channel, making it unstable.

“The computational approach allows us to model, right down to the atomic level, how small changes in protein sequence can have a major impact on signaling,” said MacDermaid, assistant professor of research at Temple’s Institute for Computational Molecular Science. “We can then use these insights to help us understand and refine our experimental and clinical work.”

The Temple researchers recreated these mutated channels and showed that one resulted in a loss of channel function. Further in vitro experiments showed that the second mutation caused the channels to be routed improperly within the cell.

Penn Vet researchers have had success in treating various forms of blindness in dogs with gene therapy, setting the stage to treat human blindness. In human achromatopsia, nearly 100 different mutations have been identified in the CNGA3 gene, including the very same one identified in the German shepherd in this study. The results, therefore, lay the groundwork for designing gene therapy constructs that can target this form of blindness with the same approach.  Science Daily  Original web page at Science Daily


* Canine influenza: Veterinarian explains what every dog owner should know about disease

Because of recent cases of canine influenza in the Chicago area, a Kansas State University veterinarian is recommending dog owners educate themselves on the respiratory disease and pay attention to where the cases are occurring. No positive cases of canine influenza, also known as dog flu, have been submitted to the Kansas State Veterinary Diagnostic Laboratory at Kansas State University in the past year. However, it is a highly contagious disease that could be contracted by dogs traveling to infected areas, which is why pet owners need to do their homework before taking their pet to another state.

“It can survive on inanimate objects like leashes, water bowls, food bowls, brushes and human clothing for 24 hours,” said Susan Nelson, clinical associate professor at Kansas State University’s Veterinary Health Center. “It can live on a person’s hands for about 12 hours, so it’s important to wash your hands and use general sanitary precautions like you would to prevent the spread of the human influenza.

The strain afflicting the dogs in Chicago is an H3N2 strain caused by a virus closely related to Asian strains currently found in southern Chinese and South Korean dog populations, according to Cornell University. It is not know to spread to humans. Almost all dogs exposed to the virus will become infected, but only about 80 percent of those dogs will show signs. Those symptoms are coughing, fever, yellowish-green colored nasal discharge, dehydration and lethargy. The other 20 percent will show no signs of sickness, but will still be contagious.

The symptoms of canine influenza are indistinguishable from the more commonly seen causes of the canine infectious respiratory disease complex, known as kennel cough, and laboratory testing is needed to confirm the diagnosis, said William Fortney, assistant professor and director for small animal outreach at the Kansas State Diagnostic Laboratory. Because of the amount of uncertainty about this possible epidemic, the lab is offering canine influenza testing at a reduced cost. For more information, contact the laboratory at 866-512-5650.

“The vast majority of these dogs have a mild form of the disease that lasts for about two to three weeks. They will get better with just supportive care,” Nelson said. “About 10 percent of these dogs can develop pneumonia, which can be fatal. In Chicago, according to reports, the more severely affected dogs have generally been less than a year old or older than 7 years old.”

Dogs typically show signs of the disease two to four days after exposure. This incubation period between exposure and when symptoms develop is when dogs are the most contagious to other dogs. Dogs can shed the virus for up to seven to 10 days after exposure, but continue to be contagious during this time. Because of this, infected dogs need to be quarantined from other dogs for about two weeks.

“My advice to dog owners is to watch the news and be aware of where the disease is across the country,” Nelson said. “Unlike human influenza, this virus is not seasonal, so it can be contracted at any time of the year. Dogs that are at greatest risk for exposure to this disease are those who frequent areas where lots of dogs are in one place, like kennels, dog shows, shelters and doggie day care facilities.”   Science Daily  Original web page at Science Daily


Ancient hybridization key to domestic dog’s origin, wolf conservation efforts

The ancestry of man’s best friend may be more complicated than its furry coat and soulful eyes betray. Understanding the evolutionary history of the domesticated dog may ultimately help protect endangered wolves, according to a study from the University of Tennessee, Knoxville

Vladimir Dinets, research assistant professor of psychology, has published an overview examining the confusing and often misunderstood system used to classify dogs and related animals such as wolves and jackals. He has proposed a logical and scientifically sound classification scheme to help make sense of all the contradictory claims. The study appears in the Vavilov Journal of Genetics and Breeding. Dinets compiled his overview by reviewing existing studies about dog classifications.

“The study shows how complex and surprising can be the evolutionary history of familiar animals we think we know perfectly well,” he said. The relationships between dogs, wolves and jackals are complicated and controversial, Dinets noted. Scientific studies and popular literature contain countless alternative ideas on their composition and the number of their species, both of which can be difficult to track.

Dinets’ overview shows that domestic dogs are descendants of two interbred species: a small extinct wild dog of Asia and the grey wolf. Different breeds have different proportions of wolf blood, and that can explain a lot about their personalities and behavior.

There are four to five wild species of Canis in North America, according to the overview. In addition to the well-known grey wolf and coyote, there is a secondary wild population of the domestic dog known as the Carolina dog, plus a few populations of hybrid origin with different proportions of wolf and coyote genes. Two of these hybrid populations, the red wolf of the eastern U.S. and the Algonquin wolf–also known as the Eastern or timber wolf–of southeastern Canada, have already evolved into full species. What is still unknown is whether they should be considered two different species or one species with two living subspecies.

“Both red wolf and Algonquin wolf are critically important components of North American ecosystems and must be protected and restored,” Dinets said. “The Carolina dog, which is also critically endangered, also deserves protection in its small natural range; it is a descendant of the first dogs brought to North America by humans at the end of the last ice age.”

The overview helps debunk claims that the red wolf is not a real species and thus not worthy of protection, he said, noting that there are persistent attempts to kill red wolf reintroduction programs. Dinets added that the critically endangered Carolina dog currently has no legal protection and animal control services treat Carolina dogs as strays and kill them. Most zoologists have not heard of it

“These species must be protected and reintroduced if we want our forests to function normally,” he said. To read Dinets’ paper on dog classification.

Read more:  Science Daily Original web page at Science Daily


Training a dog you can trust

Ane Møller Gabrielsen received her doctorate from the Norwegian University of Science and Technology (NTNU) on dogs in society and culture this spring. She opposes a Norwegian ban on six dog breeds. Norway bans ownership of pit bulls, American Staffordshire terriers (Amstaffs), Fila Brasileros, Tosa Inu, Dogo Argentinio and Czechoslovakian wolfhounds. But in the four cases where a human has been killed by a dog in the past few decades, none of the culprits were from these breeds.

The difference between dog breeds is often quite small — it is actually not possible to definitively decide the breed of a dog unless it has a complete family tree, ID chip and registration. Nonetheless, the ban on certain “dangerous” dog breeds is in many ways the essence of dog regulations in Norway. Not to say that there is no such thing as a dangerous dog, but what makes a dog dangerous has nothing to do with breed — it all comes down to treatment and training, Gabrielsen says.

Gabrielsen has the support of the Norwegian Kennel Club and several other groups in her opposition to a ban on specific dog breeds. She believes that training is the deciding factor in whether or not a dog is safe to be around, a position with which most dog owners agree. But this is where the agreement stops with a lot of dog owners. There are two main philosophies when it comes to dog training, and they do not agree.

In addition to regulations on banned dog breeds in Norway, Gabrielsen’s dissertation looks at the conflict between the two main types of dog training used today. There is of course many variations in these two training philosophies, but it is mainly the balance between punishment and reward that is the difference.

The debate between followers of the different training philosophies has often lead to heated discussions on net forums, where no one party is more polite than the other. Gabrielsen has studied this debate, and observed the way the two groups butt heads.

Gabrielsen has a dog herself, a boxer named Hilma. “My dog is trained using clicker training,” she says. Clicker training involves the training using a little device to make a clicking sound every time the dog does something right, and giving it a treat. The dog eventually learns to associate the click and the treat with that action.

Clicker training originated in the USA, and was introduced to Norway a few decades ago. Particularly younger dog owners and women tend to use reward-based training methods, and the approach is becoming more and more common. This method stems from the research of behavioural psychologists B. F. Skinner and Ivan Pavlov. It is among the dog training methods that use reward centrally. The training is easy, both for the dog and the owner

On the other side are those who believe yanking on a dog’s collar when it does something wrong is much more effective. Gabrielsen disagrees. “I’ve come to see both arguments, but i’m still completely on the side of reward. I see no reason for physical punishment,” she says.

Some people find this provoking, calling it misguided kindness, and a development in society that they don’t want any part of. The believe that only rewards won’t make your dog safe — you won’t see any results from too much kindness. “Some people draw parallels to raising children. It is important as a parent to show who is the boss,” says Gabrielsen

The idea behind this is also rooted in biology. A wolf pack has an unambiguous leader, and according to followers of this style of training, you have to be that alpha male. This is the more traditional training style, rooted in Germany and in military discipline. It is often used by older dog owners, and more commonly by men.

Maybe the emergence of reward-based training has something to do with how dogs are used in Norway. The amount of watchdogs and hunting dogs is going down. Most people who own dogs these days want a loving, happy family member. Research on dogs and the position of dogs in society has not been very common in Norway, and hasn’t always been very academic, despite the fact that it has become an increasingly popular topic.

“There are no exact numbers, but the number of dogs in Norway is estimated to have increased from 400,000 to 500,000 over the past decade,” she explains. At the same time, this means that more people need to train their dogs, and find a method that works for them. The main goal of both of these philosophies is the same — to train a dog that you can trust. But this has nothing to do with breed, Gabrielsen says.  Science Dail  Original web page at Science Daily


* Underlying cause of diabetes in dogs

In a new effort, researchers from the University of Pennsylvania and Baylor College of Medicine have used advanced imaging technology to fill in details about the underlying cause of canine diabetes, which until now has been little understood. For the first time, they’ve precisely quantified the dramatic loss of insulin-producing beta cells in dogs with the disease and compared it to the loss observed in people with type I diabetes.

“The architecture of the canine pancreas has never been studied in the detail that we have done in this paper,” said Rebecka Hess, professor of internal medicine at Penn’s School of Veterinary Medicine and a study author.

Despite important differences between the disease in dogs and humans, the study also identified key similarities that suggest investigating diabetes in dogs may yield valuable insights into treating human.

The research was led by Emily Shields, currently a graduate student in Penn’s Perelman School of Medicine, who completed much of the work as a high school and then college student in labs at Penn and Baylor. Jake A. Kushner, formerly of Penn and now McNair Medical Institute Scholar and chief of pediatric diabetes and endocrinology at Baylor College of Medicine, was senior author. Together with Hess, they collaborated with Penn Vet’s Thomas J. Van Winkle, Matthew M. Rankin of Penn Medicine and Children’s Hospital of Philadelphia and Baylor’s Carol J. Lam and Aaron R. Cox. Their study was published in PLOS ONE.

Canine diabetes can be managed with insulin, similar to type I diabetes in humans. But, unlike the human version of the disease, dogs typically develop diabetes in middle or old age, while people with type 1 diabetes are typically diagnosed during childhood. In addition, while type 1 diabetes is known to be an autoimmune condition, researchers haven’t found conclusive evidence that the same is true in dogs.

To learn more about the factors that contribute to canine diabetes, the researchers made use of a repository of donated tissue samples from dogs — 23 with diabetes and 17 without — who had been treated at Penn Vet’s Ryan Hospital and later died. The team used robotic microscopes that can rapidly move around a slide taking images of pancreas tissue samples, which were analyzed by computer to determine the contents. “In a larger view we could look at the entire cross-section of pancreas to determine how many islets there were and how big they were,” Shields said. “Then we could zoom in to differentiate beta cells, which produce insulin, from alpha cells, which produce glucagon.”

They found that beta cells dropped off in dramatic fashion in diabetic dogs, reduced 13-fold compared to non-diabetic animals. They also found that non-diabetic canine islets contained a large percentage of beta cells, comprising about 80 percent of endocrine cells. In contrast, beta cells comprise slightly more than 50 percent of endocrine cells in non-diabetic human islets. The researchers noted that this may mean that dogs need to lose more beta cells before experiencing symptoms of diabetes. The observation could explain why dogs develop a form of diabetes that is similar to type 1 diabetes, but do so later in life, compared to humans.

They also identified features of the islets and pancreatic structures that were different in dogs than in humans. “In sharp contrast to human diabetes, in which there are a lot of islets still present but none contains insulin, we found in dogs that only a few beta cells were present and the islets were incredibly small,” Kushner said.

While the researchers had hoped to be able to visualize immune cells infiltrating the pancreas and attacking beta cells, they failed to do so. While other signs point to canine diabetes being an autoimmune condition, this study did not find a “smoking gun.

Though the work highlights differences between canine and human diabetes, it also points to a number of similarities that distinguish the two from diabetes in rodents, which are often used as models to study the disease. For example, the scientists observed that dogs’ beta cells were distributed throughout the islets, as beta cells in humans are. In rodents, beta cells are concentrated in the center of the islet. “Now that we know more about the disease in dogs and in particular how they are similar to humans in ways that rodents are not, it makes them more appealing as a model,” Kushner said.

At Penn, Hess is currently working to look for genetic markers in dogs that heighten a dog’s risk of developing diabetes. “My hope is that with genetic screening we can eventually identify pre-clinical diabetic dogs, potentially making breeding recommendations that could decrease the incidence and prevalence of the disease in dogs,” Hess said.  Science Daily  Original web page at Science Daily


* Dominance in a group of dogs expressed in hard figures

The hierarchy in a group of dogs is not based on aggression but on submissiveness. A dog ranked lower in the hierarchy displays signals of submissive behaviour towards dogs ranked higher. These findings have for the first time been substantiated by means of measurements by dog researcher Joanne van der Borg of Wageningen University and colleagues based in Utrecht. They are published in the journal PLOS ONE on 26 August.

In the study into dominance, a group of dogs was placed together on working days, and stable relationships formed between them after a few months. By closely observing and analysing the exchange of seven postures and 24 behaviours by the dogs, the researchers were able to establish a hierarchy. This proved to be linear.

The suitability of signals as a measure of dominance was determined using the exchange of signals between two animals. Suitable signals are postures or behaviours which are only displayed within a relationship from animal A to animal B and not in the opposite direction. Based on the receipt of submissive signals, the dogs were ranked from high to low. They formed a linear hierarchy.

The study supports the view that the dominance in a group of dogs is not determined by aggression, as many dog owners and dog trainers believe. Aggression is found to be exhibited by higher-ranked dogs towards lower-ranked dogs but also in the opposite direction, from lower-ranked dogs towards higher-ranked dogs. For this reason, signals of aggression are not suitable as a measure of dominance.

The idea of dominance in dogs is popular among some dog trainers in various countries. They believe that dogs, like wolves, are natural born fighters with only one aim: to reach the top of the hierarchy. By contrast, a different school of thought among dog trainers holds that dominance is an outdated and obsolete notion which is not applicable to our domestic dogs. There has been much misunderstanding about the interpretation of this view, because until now there was a lack of substantiation by means of hard figures.

The signals of submissiveness from a dog meeting another member of its species can best be read from the lowering of the posture compared to the other dog. Another expression of acknowledgement of the higher status of the other individual is body-tail-wagging. This behaviour, often seen in young dogs when greeting other dogs, involves the tail moving in quite broad strokes, often with the hindquarters (the hind part of the body) moving with it. Both forms of submissiveness are an expression of ‘formal dominance’, because the context (aggression, greeting, play) does not matter. The findings are in line with previous results into dominance among wolves in captivity and Italian feral dogs.

The study contributes to our knowledge about the ways in which dogs communicate their status towards other dogs. This is important for correctly classifying the hierarchical relationship between two dogs, and probably also between human and dog. This in turn helps establish the correct diagnosis in the event of problem behaviour and will therefore improve the welfare of dogs.

Alongside the linearity of the hierarchy, Van der Borg’s research also established the gradient of the order of ranking. The graphical representation of the gradient of the hierarchy in a group of dogs is a measure of the dominance style within the group. In the group of dogs studied, this was ‘tolerant’. A steeper gradient points to a dominance style that corresponds to ‘despotic,’ while a more gentle gradient indicates ‘relaxed’ or ‘egalitarian’. The steepness of the hierarchy is a measure of an animal’s total dominance success.  Science Daily  Original web page at Science Daily


Dogs, cats, and big-wave surfers: Healthy heart lessons from animals and athletes

Heart rates of big-wave surfers are among the surprises from 30 years of studying exercise physiology in people, wild animals. For over 30 years, Terrie Williams has been studying exercise physiology in wild animals: African lions and wild dogs, dolphins and whales, coyotes and mountain lions, as well as a few human athletes. She has put mountain lions on treadmills and strapped heart-rate monitors onto big-wave surfers at Mavericks.

These studies have given Williams, a professor of ecology and evolutionary biology at UC Santa Cruz, a unique perspective on exercise and health, which she presents in an article titled “The Healthy Heart: Lessons from Nature’s Elite Athletes,” published in the September issue of the journal Physiology.

Of course, you already know the bottom line: Most people should get more exercise. Here are “Six amazing heart findings” to contemplate during your next workout:

  • One of the highest prolonged heart-rate levels ever recorded was for a professional big-wave surfer riding the monstrous swells at Mavericks: more than 180 beats per minute for three hours, with peaks of 200 beats per minute during rides.
  • Dogs and cats are opposites in terms of aerobic capacity and maximum heart rate, and humans are more like dogs, adapted for endurance exercise (chasing down prey), while cats are built for the short bursts of speed used in stalk-and-pounce hunting. This difference is reflected in heart size relative to total body mass (larger hearts in dogs and humans, smaller hearts in cats).
  • The hearts of marathon runners are 10 to 33 percent larger than those of more sedentary people.
  • Heart disease is exceedingly rare in wild animals, but it is the leading cause of death in humans worldwide. There are many plausible explanations for this, but one factor stands out above all others: the difference in daily activity levels. “We just don’t ask our hearts to do very much on a daily basis,” Williams said.
  • The mammalian dive response, automatically triggered by cold water contacting the face, involves an immediate slowing of heart rate and constriction of peripheral blood vessels to maximize blood and oxygen in the core. The mammalian exercise response has the opposite effect, increasing heart rate and metabolism. Thus, marine mammals chasing prey at depth have to balance opposing cardiovascular demands, and Williams found they can experience cardiac arrhythmias during dives.
  • Heart rate can be consciously controlled, and not just by meditating yogis. A California sea lion was trained to lower its heart rate on command while sitting out of water.

For Williams, the main reason to study exercise physiology in animals is to better understand how much energy they have to expend to live in their environments, and how they might be affected by environmental changes and human activities. Williams is also an athlete herself and has competed in a number of triathlons, so she has always been interested in what humans can learn from nature’s elite athletes. “The big difference between wild animals and humans is that they’re out there exercising for hours at a time, from the day they’re born to the day they die,” she said. “My own activity level is pretty pathetic relative to even a lion, and they’re not the most active animals. I take a lot out of these lessons from animals in terms of how much and what kinds of exercise I try to do. Mixing it up with both sprints and low-intensity exercise is the secret.”

Looking at heart rates in humans, Williams has been struck by the influence of psychological factors, as seen most dramatically in the big-wave surfers. Their high prolonged heart rates (90 percent of maximum based on treadmill tests) are induced by adrenaline, not exercise. “Just sitting on the beach before they entered the water caused the heart rates of surfers to reach almost 180 beats per minute,” Williams said.

The same phenomenon is seen in other thrill-seeking sports. Formula race car drivers and motocross racers have also been found to maintain heart rates at 90 percent of maximum for prolonged periods, though not for as long as the surfers. “The psychological component has tended to be overlooked, but you can really see it in surfers. People do these thrill-seeking sports for the adrenaline rush, and that affects the heart,” Williams said.

Is it healthy? “They’re in amazing shape overall, and I’ve never heard of any problems from a prolonged high heart rate unless there’s a pre-existing condition. But they can be exhausted for a week after battling the big waves,” she said.

Unlike human surfers, dolphins’ heart rates go down when they’re riding waves. When Williams was trying to measure heart rates of swimming dolphins, she couldn’t keep them from riding her boat’s bow wave. “They’re not doing it for the thrill; they’re just saving energy by taking the easy way out,” she said.

The discovery of cardiac arrhythmias in deep-diving marine mammals got Williams thinking about the fact that the swimming segment of triathlons accounts for over 90 percent of race day deaths, especially in cold water venues. The combination of high heart rates at the start of the race (Williams said she knows from experience that the adrenaline is flowing as racers charge into the water) and sudden immersion in cold water is an extreme challenge for the heart. It can be overwhelming for people with pre-existing cardiac conditions, she said. In response, the USA Triathlon organization issued new water temperature guidelines in 2013 for sanctioned events.  Science Daily  Original web page at Science Daily


* Countering pet obesity by rethinking feeding habits

In America, 190 million people share the luxuries of human life with their pets. Giving dogs and cats a place in human homes, beds and–sometimes even, their wills–comes with the family member package

Amongst these shared human-pet comforts is the unique luxury to overeat. As a result, the most common form of malnutrition for Americans and their companion animals results not from the underconsumption, but the overconsumption of food. The obesity epidemic also causes a similar array of diseases in people and pets: diabetes, hyperlipidemia and cancer.

During this year’s ADSA-ASAS Joint Annual Meeting, five companion animal nutrition experts from around the world further examined the implications of over- or inaccurately feeding cats and dogs. “Companion Animal Symposium: Bioenergetics of pet food” was a part of the Companion Animal Science Program, an event sponsored annually by the George Fahey Appreciation Club.

Bioenergetics concern energy flow through living systems. Since obesity results from an imbalance of energy use and intake, bioenergetics help scientists understand the correlation between overweight animals and the food they consume.

The most definitive player in pet health is the owner. Dr. Kelly Swanson, Professor of Animal and Nutritional Sciences at the University of Illinois, says the first step in combating pet obesity is simply realizing that an animal is overweight.

“Owners need to actually recognize that their pet is obese, and is not just a funny, pudgy animal that looks cute,” said Swanson. “Lean, healthy pets not only live longer, but more importantly, have a better quality of life.”

In fact, some lifelong studies show that maintaining a lean body condition score (BCS 4 or 5) adds an average of 1.8 years to dogs’ lives. Preserving steady body conditions requires owners to not just read pet food labels, but to actually understand and apply the feeding directions.

Food types and feeding frequencies also need to vary from animal to animal. Dr. Dennis Jewell, Research Scientist at Hill’s Pet Nutrition, emphasized the customization of feeding programs to fit each individual.

“Each pet has unique genetics that determine, for example, if they’re going to use more calories to maintain their body weight than other animals,” said Jewell. “We can design feeding programs for specific pet populations — based on factors like age, size, et cetera — but feeding regimens still come down to the individual pet.”

For example, weight-loss regimens equate to the feeding of less energy-dense and more fiber-dense diets. Increased fiber intake results in less ad-libitum food consumption.

One overlooked feeding strategy may lie in the nature of the food itself. According to Dr. Katherine Kerr, Post-Doctoral Research Fellow at the University of Florida, raw and whole-prey diets may provide a viable alternative to extruded ones. Her projects primarily focus on the eating patterns and nutritional health of African wildcats.

“While observing feeding behaviors, we soon recognized that felines aren’t physiologically made to chew,” said Kerr. “When feeding whole prey, they basically just crush the skull and swallow it whole.”

The diets of wild-type cats include the hide, hair and bones of prey. When used in addition to other plant and animal fibers, these have a positive impact on energy metabolism and gut microbial populations. Meat-based and whole prey diets in domestic pets could yield similar results.

Kerr says that these types of diets are undervalued and under-researched nutritional therapy options. She believes they can play an essential role in health maintenance, and disease, allergy and obesity mitigation. “The question, ‘Should we mimic nature?’ is often controversial,” said Kerr. “We need to explore these diets more to find out the answer.  Science Daily  Original web page at Science Daily


‘Golden jackals’ of East Africa are actually ‘golden wolves’

Despite their remarkably similar appearance, the “golden jackals” of East Africa and Eurasia are actually two entirely different species. The discovery, based on DNA evidence and reported in the Cell Press journal Current Biology on July 30, increases the overall biodiversity of the Canidae–the group including dogs, wolves, foxes, and jackals–from 35 living species to 36. “This represents the first discovery of a ‘new’ canid species in Africa in over 150 years,” says Klaus-Peter Koepfli of the Smithsonian Conservation Biology Institute in Washington, DC.

The new study, led by Koepfli and Robert Wayne of the University of California, Los Angeles, was inspired by recent reports suggesting that the African golden jackal was actually a cryptic subspecies of gray wolf. Those studies were based on an analysis restricted to mitochondrial DNA, which is passed along via the maternal lineage.

To expand the DNA evidence in the new study, Wayne retrieved DNA samples of golden jackals collected two decades ago in Kenya from his laboratory freezers. Koepfli and Wayne also established collaborations with colleagues, who provided them with samples from golden jackals in other parts of Africa and Eurasia. That genome-wide DNA evidence told a different story of the canids’ evolutionary past.

“To our surprise, the small, golden-like jackal from eastern African was actually a small variety of a new species, distinct from the gray wolf, that has a distribution across North and East Africa,” Wayne says. The researchers have named this previously unrecognized species the African golden wolf.

Koepfli and Wayne suspect that zoologists had mistaken African and Eurasian golden jackals for the same species because of a high degree of similarity in their skull and tooth morphology. However, the genetic data supports the idea that they are in fact two separate lineages that have been evolving independently for at least a million years. In fact, the new canid family tree suggests that these two lineages aren’t even closely related. The African species is more closely related to the lineage leading to gray wolves and coyotes than jackals, which explains their new designation as African golden wolves.

The findings come as a reminder that “even among well-known and widespread species such as golden jackals, there is the potential to discover hidden biodiversity,” with the help of genomic evidence, Koepfli says. The researchers say they will continue to study the relationships among golden jackal and wolf lineages in Africa, Eurasia, and the Middle East.  Science Daily  Original web page at Science Daily


Dogs process faces in specialized brain area, study reveals

The study involved dogs viewing both static images and video images on a screen while undergoing fMRI. It was a particularly challenging experiment since dogs do not normally interact with two-dimensional images, and they had to undergo training to learn to pay attention to the screen.

Dogs have a specialized region in their brains for processing faces, a new study finds. PeerJ is publishing the research, which provides the first evidence for a face-selective region in the temporal cortex of dogs. “Our findings show that dogs have an innate way to process faces in their brains, a quality that has previously only been well-documented in humans and other primates,” says Gregory Berns, a neuroscientist at Emory University and the senior author of the study.

Having neural machinery dedicated to face processing suggests that this ability is hard-wired through cognitive evolution, Berns says, and may help explain dogs’ extreme sensitivity to human social cues. Berns heads up the Dog Project in Emory’s Department of Psychology, which is researching evolutionary questions surrounding man’s best, and oldest, friend. The project was the first to train dogs to voluntarily enter a functional magnetic resonance imaging (fMRI) scanner and remain motionless during scanning, without restraint or sedation

In previous research, the Dog Project identified the caudate region of the canine brain as a reward center. It also showed how that region of a dog’s brain responds more strongly to the scents of familiar humans than to the scents of other humans, or even to those of familiar dogs.

For the current study, the researchers focused on how dogs respond to faces versus everyday objects. “Dogs are obviously highly social animals,” Berns says, “so it makes sense that they would respond to faces. We wanted to know whether that response is learned or innate.

The study involved dogs viewing both static images and video images on a screen while undergoing fMRI. It was a particularly challenging experiment since dogs do not normally interact with two-dimensional images, and they had to undergo training to learn to pay attention to the screen.

A limitation of the study was the small sample size: Only six of the eight dogs enrolled in the study were able to hold a gaze for at least 30 seconds on each of the images to meet the experimental criteria.

The results were clear, however, for the six subjects able to complete the experiment. A region in their temporal lobe responded significantly more to movies of human faces than to movies of everyday objects. This same region responded similarly to still images of human faces and dog faces, yet significantly more to both human and dog faces than to images of everyday objects.

If the dogs’ response to faces was learned — by associating a human face with food, for example — you would expect to see a response in the reward system of their brains, but that was not the case, Berns says.

A previous study, decades ago, using electrophysiology, found several face-selective neurons in sheep. “That study identified only a few face-selective cells and not an entire region of the cortex,” says Daniel Dilks, an Emory assistant professor of psychology and the first author of the current dog study.

The researchers have dubbed the canine face-processing region they identified the dog face area, or DFA. Humans have at least three face processing regions in the brain, including the fusiform face area, or FFA, which is associated with distinguishing faces from other objects. “We can predict what parts of your brain are going to be activated when you’re looking at faces,” Dilks says. “This is incredibly reliable across people.”

One hypothesis is that distinguishing faces is important for any social creature. “Dogs have been cohabitating with humans for longer than any other animal,” Dilks says. “They are incredibly social, not just with other members of their pack, but across species. Understanding more about canine cognition and perception may tell us more about social cognition and perception in general.”   Science Daily  Original web page at Science Daily