Category Archives: research

New dog, old tricks? Untrained stray dogs can understand human cues

If you have a dog, hopefully you’re lucky enough to know that they are highly attuned to their owners and can readily understand a wide range of commands and gestures. But are these abilities innate or are they exclusively learned through training?

To find out, a new study in Frontiers in Psychology investigated whether untrained stray dogs could understand human pointing gestures.

Dogs and gestures research

A new study shows that untrained stray dogs respond to gestures from people, suggesting that understanding between humans and dogs transcends training. Image: Shutterstock

The study revealed that about 80% of participating dogs successfully followed pointing gestures to a specific location despite having never received prior training. The results suggest that dogs can understand complex gestures by simply watching humans and this could have implications in reducing conflict between stray dogs and humans.

Dogs were domesticated 10,000–15,000 years ago, likely making them the oldest domesticated animals on the planet. Humans then bred dogs with the most desirable and useful traits so that they could function as companions and workers, leading to domesticated dogs that are highly receptive to human commands and gestures.

However, it was not clear whether dogs understand us through training alone, or whether this was innate. Can dogs interpret a signal, such as a gesture, without specific training, or even without having met the signaling person previously? One way to find out is to see whether untrained, stray dogs can interpret and react to human gestures.

Stray dogs are a common feature in cities around the world and particularly in many developing countries. While they may observe and occasionally interact with people, such dogs have never been trained, and are behaviorally “wild”. Conflicts between stray dogs and humans are a problem and understanding how humans shape stray dog behavior may help alleviate this.

To investigate, Dr. Anindita Bhadra of the Indian Institute of Science Education and Research Kolkata, India, and colleagues studied stray dogs across several Indian cities. The researchers approached solitary stray dogs and placed two covered bowls on the ground near them. A researcher then pointed to one of the two bowls, either momentarily or repeatedly, and recorded whether the dog approached the indicated bowl. They also recorded the perceived emotional state of the dogs during the experiment.

Approximately half of the dogs did not approach either bowl. However, the researchers noticed that these dogs were anxious and may have had bad experiences with humans before. The dogs who approached the bowls were noted as friendlier and less anxious, and approximately 80% correctly followed the pointing signals to one of the bowls, regardless of whether the pointing was momentary or repeated. This suggests that the dogs could indeed decipher complex gestures.

“We thought it was quite amazing that the dogs could follow a gesture as abstract as momentary pointing,” explained Bhadra. “This means that they closely observe the human, whom they are meeting for the first time, and they use their understanding of humans to make a decision. This shows their intelligence and adaptability.”

The results suggest that dogs may have an innate ability to understand certain human gestures which transcends training. However, it should be noted that the shyer, more anxious animals tended not to participate, so future studies are needed to determine more precisely how an individual dog’s personality affects their ability to understand human cues.

Overall, dogs may be more perceptive than we realize. “We need to understand that dogs are intelligent animals that can co-exist with us,” said Bhadra “They are quite capable of understanding our body language and we need to give them their space. A little empathy and respect for another species can reduce a lot of conflict.”

Original article:  Free-Ranging Dogs Are Capable of Utilizing Complex Human Pointing Cues

Source:  Frontiers Science News

Turning the page for Spot boosts literacy in young students

Reading in the presence of a pooch may be the page-turning motivation young children need, suggests a UBC researcher.

Golden retriever Abby listens

Golden retriever Abby listens while Annie Letheman (right) reads to her sister Ruby and researcher Camille Rousseau (middle) observes.

Camille Rousseau, a doctoral student in UBC Okanagan’s School of Education, recently completed a study examining the behaviour of 17 children from Grades 1 to 3, while reading with and without a dog. The study was conducted with Christine Tardif-Williams, a professor at Brock University’s department of child and youth studies.

“Our study focused on whether a child would be motivated to continue reading longer and persevere through moderately challenging passages when they are accompanied by a dog,” explains Rousseau.

Participants were recruited based on their ability to read independently. Prior to the study, each child was tested to determine their reading range and to ensure they would be assigned appropriate story excerpts. The researchers then choose stories slightly beyond the child’s reading level.

During the study’s sessions, participants would read aloud to either an observer, the dog handler and their pet or without the dog. After finishing their first page, they would be offered the option of a second reading task or finishing the session.

“The findings showed that children spent significantly more time reading and showed more persistence when a dog—regardless of breed or age—was in the room as opposed to when they read without them,” says Rousseau. “In addition, the children reported feeling more interested and more competent.”

With the recent rise in popularity of therapy dog reading programs in schools, libraries and community organizations, Rousseau says their research could help to develop ‘gold-standard’ canine-assisted intervention strategies for struggling young readers.

“There have been studies that looked at the impact of therapy dogs on enhancing students’ reading abilities, but this was the first study that carefully selected and assigned challenging reading to children,” she says.

Some studies and programs have children choose their own book, and while the reading experience would still be positive, Rousseau adds it’s the educational experience of persevering through a moderate challenge that offers a potentially greater sense of achievement.

She hopes the study increases organizations’ understanding of how children’s reading could be enhanced by furry friends.

Rousseau is continuing her research on how canine-assisted therapy can influence students in other educational contexts through UBC’s therapy dog program—Building Academic Retention through K9’s (BARK).

The study was published in Anthrozoös, a multidisciplinary journal focusing on the interactions of people and animals.

Source:  University of British Columbia media release

Study Suggests Early-Life Exposure to Dogs May Lessen Risk of Developing Schizophrenia

Ever since humans domesticated the dog, the faithful, obedient and protective animal has provided its owner with companionship and emotional well-being. Now, a study from Johns Hopkins Medicine suggests that being around “man’s best friend” from an early age may have a health benefit as well — lessening the chance of developing schizophrenia as an adult.

And while Fido may help prevent that condition, the jury is still out on whether or not there’s any link, positive or negative, between being raised with Fluffy the cat and later developing either schizophrenia or bipolar disorder.

800 Toddler with Dog_Public Domain via Wikimedia Commons

A recent study by Johns Hopkins Medicine researchers suggests that exposure to pet dogs before the age of 13 may lessen the chance of developing schizophrenia later in life. Credit: Public domain via Wikimedia Commons

 

“Serious psychiatric disorders have been associated with alterations in the immune system linked to environmental exposures in early life, and since household pets are often among the first things with which children have close contact, it was logical for us to explore the possibilities of a connection between the two,” says Robert Yolken, M.D., chair of the Stanley Division of Pediatric Neurovirology and professor of neurovirology in pediatrics at the Johns Hopkins Children’s Center, and lead author of a research paper recently posted online in the journal PLOS One.

In the study, Yolken and colleagues at Sheppard Pratt Health System in Baltimore investigated the relationship between exposure to a household pet cat or dog during the first 12 years of life and a later diagnosis of schizophrenia or bipolar disorder. For schizophrenia, the researchers were surprised to see a statistically significant decrease in the risk of a person developing the disorder if exposed to a dog early in life. Across the entire age range studied, there was no significant link between dogs and bipolar disorder, or between cats and either psychiatric disorder.

The researchers caution that more studies are needed to confirm these findings, to search for the factors behind any strongly supported links, and to more precisely define the actual risks of developing psychiatric disorders from exposing infants and children under age 13 to pet cats and dogs.

According to the American Pet Products Association’s most recent National Pet Owners Survey, there are 94 million pet cats and 90 million pet dogs in the United States. Previous studies have identified early life exposures to pet cats and dogs as environmental factors that may alter the immune system through various means, including allergic responses, contact with zoonotic (animal) bacteria and viruses, changes in a home’s microbiome, and pet-induced stress reduction effects on human brain chemistry.

Some investigators, Yolken notes, suspect that this “immune modulation” may alter the risk of developing psychiatric disorders to which a person is genetically or otherwise predisposed.

In their current study, Yolken and colleagues looked at a population of 1,371 men and women between the ages of 18 and 65 that consisted of 396 people with schizophrenia, 381 with bipolar disorder and 594 controls. Information documented about each person included age, gender, race/ethnicity, place of birth and highest level of parental education (as a measure of socioeconomic status). Patients with schizophrenia and bipolar disorder were recruited from inpatient, day hospital and rehabilitation programs of Sheppard Pratt Health System. Control group members were recruited from the Baltimore area and were screened to rule out any current or past psychiatric disorders.

All study participants were asked if they had a household pet cat or dog or both during their first 12 years of life. Those who reported that a pet cat or dog was in their house when they were born were considered to be exposed to that animal since birth.

The relationship between the age of first household pet exposure and psychiatric diagnosis was defined using a statistical model that produces a hazard ratio — a measure over time of how often specific events (in this case, exposure to a household pet and development of a psychiatric disorder) happen in a study group compared to their frequency in a control group. A hazard ratio of 1 suggests no difference between groups, while a ratio greater than 1 indicates an increased likelihood of developing schizophrenia or bipolar disorder. Likewise, a ratio less than 1 shows a decreased chance.

Analyses were conducted for four age ranges: birth to 3, 4 to 5, 6 to 8 and 9 to 12.

Surprisingly, Yolken says, the findings suggests that people who are exposed to a pet dog before their 13th birthday are significantly less likely — as much as 24% — to be diagnosed later with schizophrenia.

“The largest apparent protective effect was found for children who had a household pet dog at birth or were first exposed after birth but before age 3,” he says.

Yolken adds that if it is assumed that the hazard ratio is an accurate reflection of relative risk, then some 840,000 cases of schizophrenia (24% of the 3.5 million people diagnosed with the disorder in the United States) might be prevented by pet dog exposure or other factors associated with pet dog exposure.

“There are several plausible explanations for this possible ‘protective’ effect from contact with dogs — perhaps something in the canine microbiome that gets passed to humans and bolsters the immune system against or subdues a genetic predisposition to schizophrenia,” Yolken says.

For bipolar disorder, the study results suggest there is no risk association, either positive or negative, with being around dogs as an infant or young child.

Overall for all ages examined, early exposure to pet cats was neutral as the study could not link felines with either an increased or decreased risk of developing schizophrenia or bipolar disorder.

“However, we did find a slightly increased risk of developing both disorders for those who were first in contact with cats between the ages of 9 and 12,” Yolken says. “This indicates that the time of exposure may be critical to whether or not it alters the risk.”

One example of a suspected pet-borne trigger for schizophrenia is the disease toxoplasmosis, a condition in which cats are the primary hosts of a parasite transmitted to humans via the animals’ feces. Pregnant women have been advised for years not to change cat litter boxes to eliminate the risk of the illness passing through the placenta to their fetuses and causing a miscarriage, stillbirth, or potentially, psychiatric disorders in a child born with the infection.

In a 2003 review paper, Yolken and colleague E. Fuller Torrey, M.D., associate director of research at the Stanley Medical Research Institute in Bethesda, Maryland, provided evidence from multiple epidemiological studies conducted since 1953 that showed there also is a statistical connection between a person exposed to the parasite that causes toxoplasmosis and an increased risk of developing schizophrenia. The researchers found that a large number of people in those studies who were diagnosed with serious psychiatric disorders, including schizophrenia, also had high levels of antibodies to the toxoplasmosis parasite.

Because of this finding and others like it, most research has focused on investigating a potential link between early exposure to cats and psychiatric disorder development. Yolken says the most recent study is among the first to consider contact with dogs as well.

“A better understanding of the mechanisms underlying the associations between pet exposure and psychiatric disorders would allow us to develop appropriate prevention and treatment strategies,” Yolken says.

Source:  John Hopkins Newsroom

Unique Sled Dogs Helped the Inuit Thrive in the North American Arctic

Inuit sled dogs have changed little since people migrated with them to the North American Arctic across the Bering Strait from Siberia, according to researchers who have examined DNA from the dogs from that time span. The legacy of these Inuit dogs survives today in Arctic sled dogs, making them one of the last remaining descendant populations of indigenous, pre-European dog lineages in the Americas.

Inuit sled dogs

A team of Greenland sled dogs pulls in Greenland’s Disko Bay. The ancestors of these dogs arrived with the Inuit to the North American Arctic. (Courtesy/Tatiana Feuerborn)

The latest research is the result of nearly a decade’s work by University of California, Davis, researchers in anthropology and veterinary genetics, who analyzed the DNA of hundreds of dogs’ ancient skeletal remains to determine that the Inuit dog had significantly different DNA than other Arctic dogs, including malamutes and huskies.

Dogs continue to play role in Arctic communities

Qimmiit (dogs in Inuktitut) were viewed by the Inuit as particularly well-suited to long-distance hauling of people and their goods across the Arctic and consuming local resources, such as sea mammals, for food.

The unique group of dogs helped the Inuit conquer the tough terrain of the North American Arctic 2,000 years ago, researchers said. Inuit dogs are the direct ancestors of modern Arctic sled dogs, and although their appearance has continued to change over time, they continue to play an important role in Arctic communities.

Experts examined the DNA from 921 dogs and wolves who lived during the last 4,500 years. Analysis of the DNA, and the locations and time periods in which they were recovered archaeologically, shows dogs from Inuit sites occupied beginning around 2,000 years ago were genetically different from dogs already in the region.

According to Sacks “the genetic profiles of ancient dogs of the American Arctic dating to 2,000 years ago were nearly identical to those of older dogs from Siberia, but contrasted starkly with those of more ancient dogs in the Americas, providing an unusually clear and definitive picture of the canine replacement event that coincided with the expansion of Thule peoples across the American Arctic two millennia ago.”

Preserving an important history

Research confirms that native peoples maintained their own dogs. By analyzing the shape of elements from 391 dogs, the study also shows that the Inuit had larger dogs with a proportionally narrower cranium to earlier dogs belonging to pre-Inuit groups.

The National Science Foundation-funded portion of the research at UC Davis was inspired by Inuit activist and author Sheila Watt-Cloutier, who told Darwent about Inuit sled-dog culling undertaken by Canadian police in the 1950s and asked if there was a way to use scientific methods to tell the history and importance of sled dogs in the Arctic. Preservation of these distinctive Inuit dogs is likely a reflection of the highly specialized role that dogs played in both long-range transportation and daily subsistence practices in Inuit society.

The article, “Specialized sledge dogs accompanied the Inuit dispersal across the North American Arctic,” was published in the Proceedings of the Royal Society B: Biological Sciences.

Source:  UC Davis media release

Detection Dogs and DNA on the Trail of Endangered Lizards

Detection dogs trained to sniff out the scat of an endangered lizard in California’s San Joaquin Valley, combined with genetic species identification, could represent a new, noninvasive sampling technique for lizard conservation worldwide. That is according to a study published by the University of California, Davis, in partnership with the nonprofit Working Dogs for Conservation, U.S. Geological Survey and the U.S. Bureau of Land Management.

Scientists have used trained conservation dogs to locate scat and collect DNA samples for everything from bears and foxes to gorillas and whales. But the technique had not been used for reptiles until this study, for which scientists developed a novel approach to identify the presence of the blunt-nosed leopard lizard in the Panoche Hills Recreation Area and Carrizo Plain National Monument, both managed by BLM.

They developed new methods to recover DNA from feces and genetically identify lizard species in the same area. The study, published in the Journal of Wildlife Management, is a proof of concept for a host of reptiles.

Lizard detection dog

Seamus, a trained detection dog, alerts his handler to the presence of scat. (Mike Westphal, Bureau of Land Management)

“So many reptilian species have been hit so hard,” said lead author Mark Statham, an associate researcher with the Mammalian Ecology and Conservation Unit of the UC Davis School of Veterinary Medicine. “A large proportion of them are endangered or threatened. This is a really valuable way for people to be able to survey them.”

No direct contact needed

Current methods for surveying lizard species typically rely on live capture or visual surveys. Scat sampling allows biologists to study elusive, rare or dangerous animals without the need for direct contact. In addition to informing about the presence, habitat and genetics of an animal, scat can also be analyzed to inform researchers about diet, hormones, parasites and other health factors.

Using the new method, the authors genetically identified specific species for 78 percent of the 327 samples collected by dog-handler teams across four years. Most (82 percent) of those identified were confirmed as being from blunt-nosed leopard lizards.

To meet regulatory monitoring requirements, more research is needed to assess the viability of using detection dogs to recover usable DNA at larger scales. But the research highlights the broad potential this method holds for surveying and monitoring reptiles.

Funding was provided by the Bureau of Land Management.

Source:  UC Davis media release

Does training method matter?: Evidence for the negative impact of aversive-based methods on companion dog welfare

Your dog may be the apple of your eye, but let’s be honest: she is an animal, with her own instincts and idiosyncrasies, and there are going to be times when she makes you want to tear your hair out.

Much you want to, however, new research suggests that you should never yell at or otherwise punish a mischievous mutt.

No Yelloing

Photo ref: smrm1977/iStock

According to a new study uploaded to pre-print server bioRxiv, aversive training such as positive punishment and negative reinforcement can have long-term negative effects on your dog’s mental state.

“Our results show that companion dogs trained using aversive-based methods experienced poorer welfare as compared to companion dogs trained using reward-based methods, at both the short- and the long-term level,” the researchers write in their paper.

“Specifically, dogs attending schools using aversive-based methods displayed more stress-related behaviours and body postures during training, higher elevations in cortisol levels after training, and were more ‘pessimistic’ in a cognitive bias task.”

This sort of research has been conducted before, and found that aversive training has negative effects, but it’s primarily been on police and laboratory dogs. In addition, the aversive training tends to be shock collar training, which is only one of several tools used.

So, led by biologist Ana Catarina Vieira de Castro of the Universidade do Porto in Portugal, the international team of researchers conducted their new study on companion dogs.

The animals were recruited from a number of training schools in Porto – 42 dogs from three schools that use reward-based training like food treats or play, and 50 dogs from four schools that use aversive-based training, such as yelling, physically manipulating the dog, or leash-jerking.

Each dog was filmed during the first 15 minutes of three training sessions, and saliva samples were taken to assess stress levels from training – three from each dog relaxing at home to establish baseline levels of stress hormone cortisol, and three from each dog after training.

The researchers also analysed the dogs’ behaviour during training to look for stress behaviours, such as yawning, lip-licking, paw-raising and yelping.

Unsurprisingly, the dogs in the aversive training classes showed elevated stress behaviours, particularly yawning and lip-licking. Their saliva also had significantly increased levels of cortisol compared to when they were relaxing at home.

By contrast, the positive reinforcement dogs were pretty chill – far fewer stress behaviours, and much more normal cortisol levels.

The next step was to assess the longer term effects of this stress. A month after the dogs were assessed at training, 79 of them were then trained to associate a bowl on one side of a room with a sausage snack. If the bowl was on that side, it always held a delicious treat; if located on the other side, the bowl never had the treat. (All bowls were rubbed with sausage to ensure the smell didn’t give the game away.)

Then, the researchers moved the bowls around the room to ambiguous locations to see how quickly the dogs would approach in search of the treat. Higher speed was interpreted to mean the dog was anticipating a mouthful of deliciousness, whereas a slower speed meant the dog was more pessimistic about the bowl’s contents.

Sure enough, the more aversive training a dog had received, the more slowly it approached the bowl. Interestingly, dogs from the reward-based training group actually learnt the bowl location task faster than the aversive-training dogs.

This suggests that reward-based training may actually be more effective, although the researchers suggest this may be because the dogs already understand treat-based training methods. It’s possible that the other group would learn more quickly were an aversive method applied – more research needs to be done to determine this.

Overall, though, the results seem to imply that aversive training doesn’t necessarily have an edge over reward training, and that reward training is much better for your dog’s happiness.

“Critically,” the researchers said, “our study points to the fact that the welfare of companion dogs trained with aversive-based methods appears to be at risk.”

The full paper is available on bioRxiv ahead of peer review.

Source:  Sciencealert

AI could help diagnose dogs suffering from chronic pain

A new artificial intelligence (AI) technique developed by the University of Surrey could eventually help veterinarians quickly identify Cavalier King Charles Spaniel (CKCS) dogs with a chronic disease that causes crippling pain. The same technique identified unique biomarkers which inspired further research into the facial changes in dogs affected by Chiari-like malformation (CM).

CKCS

Photo by Getty Images

Cavalier King Charles Spaniels are predisposed to CM – a disease which causes deformity of the skull, the neck (cranial cervical vertebrae) and, in some extreme cases, lead to spinal cord damage called syringomyelia (SM). While SM is straightforward to diagnose, pain associated with CM is challenging to confirm and why this research is innovative.

In a paper published by the Journal of Veterinary Internal Medicine, researchers from Surrey’s Centre for Vision, Speech and Signal Processing (CVSSP) and School of Veterinary Medicine (SVM) detail how they used a completely automated, image mapping method to discover patterns in MRI data that could help vets identify dogs that suffer from CM associated pain. The research helped identify features that characterise the differences in the MRI images of dogs with clinical signs of pain associated with CM and those with syringomyelia from healthy dogs. The AI identified the floor of the third ventricle and its close neural tissue, and the region in the sphenoid bone as biomarkers for pain associated with CM and the presphenoid bone and the region between the soft palate and the tongue for SM.

Dr Michaela Spiteri, lead author of the study from CVSSP, said: “The success of our technique suggests machine learning can be developed as a diagnostic tool to help treat Cavalier King Charles Spaniel’s that are suffering from this enigmatic and terrible disease. We believe that AI can be a useful tool for veterinarians caring for our four-legged family members.”

Identification of these biomarkers inspired a further study, also published in the Journal of Veterinary Internal Medicine, which found that dogs with pain associated with CM had more brachycephalic features (having a relatively broad, short skull) with reduction of nasal tissue and a well-defined stop.

SVM student, Eleonore Dumas, whose 3rd year project formed part of the study data, said: “Being able to contribute to the development of diagnostic tools that allow for earlier diagnosis of patients suffering from this painful condition has been both challenging and incredibly rewarding.”

Dr Penny Knowler, lead author of the study from SVM, said: “This study suggests that the whole skull, rather than just the hindbrain, should be analysed in diagnostic tests. It also impacts on how we should interpret MRI from affected dogs and the choices we make when we breed predisposed dogs and develop breeding recommendations.”

Adrian Hilton, Distinguished Professor from the University of Surrey and Director of CVSSP, said: “This project demonstrates the potential for AI using machine learning to provide new diagnostic tools for animal health. Collaboration between experts in CVSSP and Surrey’s School of Veterinary Medicine is pioneering new approaches to improve animal health and welfare.”

Both studies were funded by the Memory of Hannah Hasty Research Fund. Hannah was a CKCS unaffected by CM/ SM and a much beloved companion, giving her owner much support and joy. The AI study was also supported by the Pet Plan Charitable Trust.

The findings of the studies are available to read on the Journal of Veterinary Internal Medicine website here and here.

Our ability to read dogs’ facial expressions is learned, not innate

In a recent study published in Scientific Reports, a team of researchers from Germany and the United Kingdom assessed how experience with dogs affects humans’ ability to recognize dog emotions. Participants who grew up in a cultural context with a dog-friendly attitude were more proficient at recognizing dog emotions. This suggests that the ability to recognize dogs’ expressions is learned through age and experience and is not an evolutionary adaptation.

Facial expressions study

The study used photos of dogs with wolf-like faces and upright ears for emotion recognition © Juliane Bräuer

Dogs were the first domesticated animal, with humans and dogs sharing more than 40,000 years of social interactions and life together. According to the co-domestication hypothesis, this process allowed humans and dogs to evolve special emotional signals and cognitive skills that favor mutual understanding. We know, for example, that over the millennia, dogs have evolved the ability to understand human words, iconic signs, and other gestures, and research has shown that dogs can even use tone of voice and facial expressions to recognize human emotions. Beyond personal testimony from dog lovers, however, little attention has been paid to how well humans can understand their canine counterparts.

In the current study, led by Federica Amici of the Max Planck Institute for Evolutionary Anthropology and Juliane Bräuer of the Max Planck Institute for the Science of Human History, the researchers set out to understand how well humans can understand the emotional displays of dogs, and where that understanding comes from.

How well do we understand our species’ best friend?

In order to test how well humans can understand the emotions behind dog facial expressions, researchers collected photographs of dogs, chimpanzees, and humans displaying either happy, sad, angry, neutral, or fearful emotions as substantiated by the photographers. They then recruited 89 adult participants and 77 child participants and categorized them according to their age, the dog-positivity of their cultural context, and the participants’ personal history of dog ownership.

Each participant was presented with photographs of dogs, chimps, and humans, and asked to rate how much the individual in the picture displayed happiness, sadness, anger, or fear. Adults were also asked to determine the context in which the picture had been taken (e.g., playing with a trusted conspecific partner; directly before attacking a conspecific). The results of the study showed that, while some dog emotions can be recognized from early on, the ability to reliably recognize dog emotions is mainly acquired through age and experience. In adults, the probability of recognizing dog emotions was higher for participants who grew up in a cultural context with a positive attitude towards dogs, regardless of whether they owned a dog themselves.

Without a dog-positive context, we could be barking up the wrong tree

A dog-postive cultural background, one in which dogs are closely integrated into human life and considered highly important, may result in a higher level of passive exposure and increased inclination and interest in dogs, making humans better at recognizing dogs’ emotions even without a history of personal dog ownership. “These results are noteworthy,” says Amici, “because they suggest that it is not necessarily direct experience with dogs that affects humans’ ability to recognize their emotions, but rather the cultural milieu in which humans develop.”

The researchers also found that regardless of age or experience with dogs, all participants were able to identify anger and happiness reliably. While these results may suggest an innate ability favored by the co-domestication hypothesis, it is also possible that humans learn to recognize these emotions quickly, even with limited exposure. Other than anger and happiness, the children in the study were not good at identifying dog emotions. They recognized anger and happiness more reliably in dogs than in chimps, but otherwise identified dog emotions as poorly as they did chimpanzee emotions, suggesting that the ability to understand how dogs are feeling is not innate.

“We think it would be valuable to conduct future studies that seek to determine exactly which cultural aspects affect one’s ability to read dog emotions, and to include real-life stimuli and body expressions in addition to instructed stimuli and facial expressions,” states Bräuer. “In this way, we could develop a better understanding of inter-cultural variation in emotion recognition. Hopefully this information could be used to reduce the occurrence of negative incidents between humans and dogs that are caused by humans’ inability to read dog signals.”

Source:  Max Planck Institute for the Science of Human History

 

Your dog might be hiding its true colors

If you have a purebred dog, it’s likely that he or she looks fairly similar to other dogs of the same breed, especially when it comes to the color of their coats.

But what happens if a purebred puppy doesn’t look exactly like its siblings when it’s born? Chances are, it might not be a flaw – but rather a hidden gene variant that decided to show itself.

New research from Purdue University’s College of Veterinary Medicine shows that some breeds of dogs have hidden coat colors – and in some cases, other traits – that have been lurking all along.

Purdue university research into coat color

New research from Purdue University’s College of Veterinary Medicine shows that some breeds of dogs have hidden coat colors – and in some cases, other traits – that have been lurking all along. Example: There are around 18 recognized breeds of dogs that have the genetic potential to be born without a tail – such as the popular Australian Shepherd (shown in photo). But the data shows that up to 48 of the breeds analyzed possess the tailless gene variant, usually at a very low frequency.

Led by Kari Ekenstedt, DVM, Ph.D., assistant professor of anatomy and genetics, and Dayna Dreger, Ph.D., the lead scientist in Ekenstedt’s canine genetics research laboratory, the team looked at a dozen different genes in 212 dog breeds. Purdue researchers, together with industry partners at Wisdom Health, analyzed data that had been initially collected by WISDOM PANEL™ for the development of canine DNA tests. The work was published Oct. 28 in PLOS ONE.

“These are purebred dogs with traits that their breed clubs say they’re not supposed to have,” said Ekenstedt, whose research program focuses on canine genetics. “The message of this paper is, ‘Hey, these gene variants exist in your breed, and if a few dogs are born with these traits, it’s not caused by accidental breeding and it’s not a mutt; it’s a purebred showing this known genetic potential.’”

Along with analyzing the data, researchers used standard breed descriptions from major American and international dog breed registries to determine coat colors and tail lengths that were accepted within each breed.

“There was a lot of information we didn’t expect,” Dreger said. “When it comes to different dog breeds, their standards are mostly based on preference and aesthetics. We make assumptions for certain breeds based on what we expect their coat colors to be.”

Ekenstedt says coat color genes have a significant amount of epistasis between them, meaning that what happens at one gene can mask what’s happening at another gene. Because of epistasis, it’s rare to see those masked genes actually expressed in a dog’s coat color.

One example of a “fault” allele – a gene variant that would cause a trait that is not allowed in a breed standard – is an allele that causes the brown color, which affects both hair pigment and skin pigment. The color is allowed in breeds like the Labrador Retriever where it causes the chocolate color. However, researchers observed that in breeds where brown is not allowed, such as the Rottweiler and the German Shepherd Dog, brown alleles exist at low frequencies.

Another example of a fault allele is in the Weimaraner, which exists in both longhaired and shorthaired varieties. At least one dog breed organization does not allow longhaired Weimaraners while several others do allow them.  Of the Weimaraners sampled in this data, the longhaired allele is present at a 4% frequency.

The same goes for other traits, too, Dreger said. For example, there are around 18 recognized breeds of dogs that have the genetic potential to be born without a tail – such as the popular Australian Shepherd. But the data shows that up to 48 of the breeds analyzed possess the tailless gene variant, usually at a very low frequency; one of those breeds is the Dachshund.

“A breeder would certainly be surprised to see a Dachshund born without a tail,” Dreger said. “The chances are low, but our research shows that the potential is there.”

Both Dreger and Ekenstedt hope the research prompts some discussions within the dog community.

“I want this to start science-based conversations,” Dreger said. “We’re not here to make decisions on what a breed should or shouldn’t look like or what a breed club should do. We’re here to say these are the facts, and these are the gene variants that naturally exist in these breeds.”

They also hope it changes some perspectives when it comes to what is to be expected with certain breeds of dogs.

“There’s an assumption that the standards for these different breeds of dogs are set in stone,” Dreger said. “People will often make assumptions that if it doesn’t match this, it’s not purebred. This data shows that there is a lot of variation in some of these breeds, and the standards are not as concrete as we expect them to be.”

Wisdom Health funded a Veterinary Summer Scholar position to Blair Hooser, a student at the Purdue College of Veterinary Medicine and coauthor on the paper, for this work. Partial support for Dr. Ekenstedt was provided by the National Institutes of Health.

Source:  Purdue University media release

Estrogen’s opposing effects on mammary tumors in dogs

Dogs that are spayed at a young age have a reduced risk of developing mammary tumors, the canine equivalent of breast cancer. Early spaying reduces levels of estrogen production, leading many veterinarians and scientists to cast estrogen in a negative light when it comes to mammary cancer.

But the effects of estrogen on cancer risk in dogs aren’t straightforward, according to a new study led by researchers from Penn’s School of Veterinary Medicine. While it’s clear that spaying dogs greatly minimizes their risk of developing mammary cancer, the findings suggest that the practice may increase the risk of more aggressive cancers. And in spayed animals with mammary tumors, the team found that higher serum estrogen levels were actually protective, associated with longer times to metastasis and improved survival times.

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Veterinary oncologist Karin Sorenmo and colleagues cast new light on the complex role of estrogen in canine mammary cancer. The research emerged from Penn Vet’s Shelter Canine Mammary Tumor Program, which assists in treating and then finding homes for dogs like Brownie, pictured with former oncology intern, Kiley Daube.

“Dogs that remain intact and have their ovaries develop many more mammary tumors than dogs that were spayed, so removing that source of estrogen does have a protective effect,” says Karin U. Sorenmo, a veterinary oncologist at Penn Vet and senior author on the study, published in PLOS ONE. “Estrogen does seem to drive mammary cancer development. But what it does for progression to metastasis—that I think is more complicated.”

Sorenmo and colleagues have been studying mammary tumors in dogs as a way of improving care and treatment for pets but also to make insights into human breast cancer biology.

“Much of the research we do in veterinary medicine looks at what is done in people and then adapts it,” she says. “But dogs are such a great, comprehensive model for cancer. Yes, there are differences in biology between dogs and people, but here those differences may allow us to ask very probing questions about what estrogen is doing in both dogs with mammary cancer and women with breast cancer.”

The research used data from two prospective studies, including one involving dogs in the Penn Vet Shelter Canine Mammary Tumor Program, through which shelter dogs with mammary tumors receive treatment, are studied by researchers like Sorenmo, and then find foster or permanent homes.

The team evaluated 159 dogs with mammary cancer, 130 that were spayed as part of the study and 29 that remain intact. In addition to surgically removing the dogs’ measurable tumors, the team collected information on serum estrogen levels, tumor type, disease grade and stage, time to metastasis, and survival time.

Despite estrogen’s link with an increased risk of developing mammary tumors, the researchers found that higher serum estrogen levels also seemed to help dogs avoid some of the riskiest aspects of their disease. Unexpectedly, when dogs were spayed at the same time their tumors were removed, those with estrogen receptor-positive tumors that had higher serum estrogen took longer to develop metastatic disease and survived longer than dogs with lower estrogen levels, confirming that these tumors depended on estrogen for progression.

Sorenmo speculates that, in these cases, estrogen’s action may be nuanced. “It drives the cancer, but it also seems to control or modulate it, reining it in,” she says, because most dogs with high serum estrogen levels had lower-grade and estrogen receptor-positive tumors, rendering them susceptible to hormonal deprivation by spaying.

The protective role of estrogen was also surprisingly pronounced in dogs with estrogen-receptor negative mammary tumors. In these higher-risk cancers, high serum estrogen was associated with delayed or absent metastasis. Complementing these findings and supporting a potential broader, tumor receptor-independent anti-cancer effect driven by estrogen, dogs with low serum estrogen had a significantly increased risk for developing other non-mammary aggressive fatal tumors, such as hemangiosarcoma, during their follow-up after mammary tumor surgery.

Some of the findings contradict what has been found in women with breast cancer. For example, higher serum estrogen levels in women following breast cancer therapy have been associated with higher rates of recurrence. But Sorenmo also notes that many cases of breast cancer in women arise just after menopause, when estrogen levels tumble. So there may be a more complex role for estrogen in people’s cancer risk as well.

The work points to new possibilities for examining the role of estrogen in cancer initiation and progression. Already, Sorenmo and colleagues, including Penn Vet’s Susan Volk and Ellen Puré, are pursuing investigations of how the hormone affects the tumor microenvironment, cells that aren’t themselves cancerous but may either stem or encourage a tumor’s growth and spread.

“I think this study opens some really complicated questions,” Sorenmo says. “If we start dissecting exactly what estrogen is doing, what genes or immune cells it’s interacting with, maybe we could harness the power of estrogen to be more clever in our treatment strategies.”

Source:  Penn Today