Category Archives: research

Most dog breeds highly inbred

Dog breeds are often recognized for distinctive traits — the short legs of a dachshund, wrinkled face of a pug, spotted coat of a Dalmatian. Unfortunately, the genetics that give various breeds their particular attributes are often the result of inbreeding.

A study shows the majority of canine breeds are highly inbred, contributing to an increase in disease and health care costs throughout their lifespan. (Getty)

In a recent study published in Canine Medicine and Genetics, an international team of researchers led by University of California, Davis, veterinary geneticist Danika Bannasch show that the majority of canine breeds are highly inbred, contributing to an increase in disease and health care costs throughout their lifespan.

“It’s amazing how inbreeding seems to matter to health,” Bannasch said. “While previous studies have shown that small dogs live longer than large dogs, no one had previously reported on morbidity, or the presence of disease. This study revealed that if dogs are of smaller size and not inbred, they are much healthier than larger dogs with high inbreeding.”

Inbreeding affects health

The average inbreeding based on genetic analysis across 227 breeds was close to 25%, or the equivalent of sharing the same genetic material with a full sibling. These are levels considered well above what would be safe for either humans or wild animal populations. In humans, high levels of inbreeding (3-6%) have been associated with increased prevalence of complex diseases as well as other conditions.

“Data from other species, combined with strong breed predispositions to complex diseases like cancer and autoimmune diseases, highlight the relevance of high inbreeding in dogs to their health,” said Bannasch, who also serves as the Maxine Adler Endowed Chair in Genetics at the UC Davis School of Veterinary Medicine.

The researchers partnered with Wisdom Health Genetics, a world leader in pet genetics, to obtain the largest sample size possible for analysis. Wisdom Health’s database is the largest dog DNA database in the world, helping researchers collect data from 49,378 dogs across 227 breeds — primarily from European sources.

Some breeds more inbred

So, what makes a dog breed more inbred than others? Bannasch explained that it’s often a combination of a small founding population followed by strong selection for particular traits in a breed — often based on looks rather than purpose. While she has always had an interest in the population structure of some of these breeds, she became particularly interested in the Danish-Swedish farmdog several years ago. She fell in love with their compact size, disposition and intelligence, and ended up importing one from Sweden.

Bannasch discovered that Danish-Swedish farmdogs have a low level of inbreeding based on their history of a relatively large founding population of 200, and being bred for function, rather than a strong artificial selection for looks. And according to the insurance health data on breeds collected from Agria Insurance Sweden and hosted online by the International Partnership for Dogs, the farmdog is one of the healthiest breeds.

The study also revealed a significant difference in morbidity between brachycephalic (short skull and snout) and non-brachycephalic breeds. While that finding wasn’t unexpected, the researchers removed brachycephalic breeds from the final analysis on effects of inbreeding on health.

Preserving genetic diversity

In the end, Bannasch said she isn’t sure there is a way out of inbred breeds. People have recognized that creating matches based solely on pedigrees is misleading. The inbreeding calculators don’t go back far enough in a dog’s genetic line, and that method doesn’t improve overall high levels of population inbreeding.

There are other measures that can be taken to preserve the genetic diversity and health of a breed, she said. They include careful management of breeding populations to avoid additional loss of existing genetic diversity, through breeder education and monitoring of inbreeding levels enabled by direct genotyping technologies.

Outcrosses are being proposed or have already been carried out for some breeds and conditions as a measure to increase genetic diversity, but care must be taken to consider if these will effectively increase overall breed diversity and therefore reduce inbreeding, Bannasch said. In particular, in the few breeds with low inbreeding levels, every effort should be made to maintain the genetic diversity that is present.

Source: UC Davis

Common household noises may be stressing your dog

Researchers at the University of California, Davis, have found that people may not recognize that their dog is stressed when exposed to common household noises. While it’s well established that sudden loud noises, such as fireworks or thunderstorms, commonly trigger a dog’s anxiety, a new study finds even common noises, such as a vacuum or microwave, can be a trigger.

UC Davis study finds even common household items like a vacuum cleaner can cause stress and anxiety for dogs. (Photo: Getty)

The study was published in Frontiers in Veterinary Science.

The research found that high-frequency, intermittent noises such as the battery warning of a smoke detector are more likely to cause a dog anxiety, rather than low-frequency, continuous noise.

“We know that there are a lot of dogs that have noise sensitivities, but we underestimate their fearfulness to noise we consider normal because many dog owners can’t read body language,” said lead author Emma Grigg, a research associate and lecturer at the UC Davis School of Veterinary Medicine.

Signs of anxiety

Some common signs of a dog’s anxiety include cringing, trembling or retreating, but owners may be less able to identify signs of fear or anxiety when behaviors are more subtle. For example, stressed dogs could pant, lick their lips, turn their head away or even stiffen their body. Sometimes their ears will turn back, and their head will lower below their shoulders. Grigg suggests owners better educate themselves on anxiety-related behavior.

Researchers conducted a survey of 386 dog owners about their dogs’ responses to household sounds and examined recorded dog behaviors and human reactions from 62 videos available online. The study found that owners not only underestimated their dogs’ fearfulness, but the majority of people in videos responded with amusement rather than concern over their dog’s welfare.

“There is a mismatch between owners’ perceptions of the fearfulness and the amount of fearful behavior actually present. Some react with amusement rather than concern,” Grigg said. “We hope this study gets people to think about the sources of sound that might be causing their dog stress, so they can take steps to minimize their dog’s exposure to it.”

Some sounds painful for dogs

Grigg said because dogs have a wider range of hearing, some noises could also be potentially painful to a dog’s ears, such as very loud or high-frequency sounds. She said minimizing exposure may be as simple as changing batteries more frequently in smoke detectors or removing a dog from a room where loud noises might occur.

“Dogs use body language much more than vocalizing and we need to be aware of that,” said Grigg. “We feed them, house them, love them and we have a caretaker obligation to respond better to their anxiety.”

Source: UC Davis

Many new college students report pet separation anxiety

Pets are not the only ones who experience separation anxiety; their people do too.

Washington State University researchers surveyed a sample of new first-year college students leaving pets at home and found that 75% experienced some level of pet separation anxiety—with one in four reporting moderate to severe symptoms.

“Students who are struggling with missing their pets should know that they’re not alone,” said Alexa Carr, the lead author of the study which is part of her WSU doctoral dissertation. “There’s nothing necessarily wrong with them if they are experiencing a lot of distress from leaving their pets. It can be an isolating experience to lose that coping resource.”

The students who had higher anxiety tended to be those who treated their pets more like people, identifying them as friends, sleeping in the same room and generally spending a lot of time with them. Interestingly, students who had dogs at home also tended to report more attachment to their pets—and more separation anxiety—than those with cats and other types of pets.

While there are many anecdotal accounts of students missing their pets, the study published in Anthrozoos, is the first known research investigating this kind of pet separation anxiety in humans.

Carr and co-author Patricia Pendry, a WSU associate professor of human development, surveyed a sample of about 150 incoming first-year students who had pets at home. The vast majority of respondents, 81%, were women—which is a limitation of the study but also consistent with trends in college enrollment. In 2020, 60% of enrolled college students were women, according to National Center for Education Statistics.

A woman with dark hair smiling and holding a black cat on her shoulder
Alexa Carr

The researchers surveyed the group before they arrived on campus and after their first two weeks of the semester in fall 2019 before the pandemic forced many universities online. The students answered questions related to their mental health, attachment to their pets and feelings about leaving them behind.

Even after controlling for pre-existing mental health issues, the researchers found that pet-related separation anxiety was very strong in the group during the transition to college, especially among students who were closely attached to their pets.

The findings indicate this is an issue for many students and should be taken seriously by campus counselors, Carr said. It also has implications for pet visitation programs now popular at many U.S.  universities which bring animals to campus to help stressed students. A previous WSU study found that petting dogs or cats for just 10 minutes lowers levels of the stress hormone cortisol.

The authors said more research is needed to understand the implications of pet separation anxiety. For example, whether students’ symptoms are stable or become less severe over the course of the semester; or whether pet visitation programs might have some unintended effects, such as potentially exacerbating separation anxiety for students missing their specific pets back home.

The researchers also cautioned that this study should not be used as justification for students to bring their pets with them when they go to college, particularly if they would be their sole caregivers.

“It’s a big responsibility to take care of an animal and would a student then able to balance their school responsibilities, social lives and jobs?” Carr said. “There are more things to take into consideration and explore before we could advocate for more pets on campus.”

Source: WSU Insider

Behaviour resembling human ADHD seen in dogs

A study involving some 11,000 dogs carried out at the University of Helsinki demonstrated that the gender, age and breed of the dog, as well as any behavioural problems and certain environmental factors, are connected to hyperactive and impulsive behaviour and inattention (ADHD).

(Image: Mostphotos)

“Our findings can help to better identify, understand and treat canine hyperactivity, impulsivity and inattention. Moreover, they indicated similarity with human ADHD, consolidating the role of dogs in ADHD-related research,” says Professor Hannes Lohi, head of a canine gene research group at the University of Helsinki.

“Dogs share many similarities with humans, including physiological traits and the same environment. In addition, ADHD-like behaviour naturally occurs in dogs. This makes dogs an interesting model for investigating ADHD in humans,” says doctoral researcher Sini Sulkama.

Professor Lohi’s research group collected data on more than 11,000 dogs by conducting an extensive behavioural survey. Hyperactivity, impulsivity and inattention were examined using questions based on a survey utilised in human ADHD research. The goal of the study was to identify environmental factors underlying canine ADHD-like behaviour and potential links to other behavioural traits.

The dog’s age and gender as well as the owner’s experience of dogs make a difference

“We found that hyperactivity, impulsivity and inattention were more common in young dogs and male dogs. Corresponding observations relating to age and gender in connection with ADHD have been made in humans too,” says Jenni Puurunen, PhD.

Dogs who spent more time alone at home daily were more hyperactive, impulsive and inattentive than dogs who spent less time on their own.

“As social animals, dogs can get frustrated and stressed when they are alone, which can be released as hyperactivity, impulsivity and inattention. It may be that dogs who spend longer periods in solitude also get less exercise and attention from their owners,” Sulkama muses.

The researchers discovered a new link between hyperactivity and impulsivity, and the owner’s experience with dogs, as the two traits were more common in dogs who were not their owners’ first dogs. The causality of this phenomenon remains unclear.

“People may pick as their first dog a less active individual that better matches the idea of a pet dog, whereas more active and challenging dogs can be chosen after gaining more experience with dogs,” explains Sulkama.

Significant differences between breeds

Breeding has had a significant effect on the breed-specific behaviour of different dog breeds. Differences between breeds can also indicate genes underlying the relevant traits.

“Hyperactivity and impulsivity on the one hand, and good concentration on the other, are common in breeds bred for work, such as the German Shepherd and Border Collie. In contrast, a more calm disposition is considered a benefit in breeds that are popular as pets or show dogs, such as the Chihuahua, Long-Haired Collie and Poodle, making them easier companions in everyday life. Then again, the ability to concentrate has not been considered as important a trait in these breeds as in working breeds, which is why inattention can be more common among pet dogs,” Professor Lohi says.

Link to other behavioural problems

The study confirmed previously observed interesting links between hyperactivity, impulsivity and inattention, and obsessive-compulsive behaviour, aggressiveness and fearfulness. ADHD is also often associated with other mental disorders and illnesses. For example, obsessive-compulsive disorder (OCD) often occurs in conjunction with ADHD. In dogs, OCD-like obsessive-compulsive behaviour can appear as, among other things, tail chasing, continuous licking of surfaces or themselves, or staring at ‘nothing’.

“The findings suggest that the same brain regions and neurobiological pathways regulate activity, impulsivity and concentration in both humans and dogs. This strengthens the promise that dogs show as a model species in the study of ADHD. In other words, the results can both make it easier to identify and treat canine impulsivity and inattention as well as promote ADHD research,” Sulkama sums up.

Funding

This study was part of the Academy of Finland project investigating the epidemiology of canine behaviour and related environmental and genetic factors and metabolic changes. This study was also supported by the European Research Council (Starting Grant), the ERA-NET NEURON funding platform and the Jane and Aatos Erkko Foundation.

Original article

Sulkama S, Puurunen J, Salonen M, Mikkola S, Hakanen E, Araujo C, Lohi H. Canine hyperactivity, impulsivity, and inattention share similar demographic risk factors and behavioural comorbidities with human ADHD. Transl Psychiatry. 2021 Oct 1;11(1):501. doi: 10.1038/s41398-021-01626-x.

Source: University of Helsinki

Survey finds a need for pet care during hospitalizations

It’s hard to heal in your hospital bed if you’re concerned about your pets at home.

Credit: Bryan McCullough

Tiffany Braley, M.D., M.S., an associate professor of neurology at University of Michigan Health, was surprised when a patient she was caring for explained why they needed to go home from the hospital as soon as possible: their pets.

After she heard several more patients voice concern for their cats, dogs and other animals at home as they sat in the hospital, she soon realized that this occurrence was not uncommon. In many cases, it involved patients who were the sole caregivers for their pets.

“I’ve had patients with acute strokes explain to me that they needed to get home to their pets, even though it was in their best medical interest to be admitted or remain in the hospital,” Braley said. “Through these interactions, it became evident to me that we needed to learn more about the scope of this problem and how we could find better ways to address it.”

Braley, who also loves animals, then reached out to fellow animal lover colleagues in neurology, social work, nursing, and U-M’s Office of Patient Experience to investigate this question.  The first step: learning about pet owner experiences from Michigan Medicine’s own patient advisors.

Study results

In partnership with U-M’s Office of Patient Experience, Braley and colleagues sent a survey to patient and family advisors who previously offered to help share their experiences to improve the patient experience. The purpose of the survey was to understand how a need to care for animals at home might affect how hospitalized patients follow their doctors’ recommendations.

Researchers published their findings in the Journal of Patient Experience.

More than half of the 113 people who responded to the survey (63%) reported difficulty figuring out pet care during their own hospitalization and/or that of a loved one.

Nearly a third reported that pet care needs impacted their decision, the decision of someone they knew, or both, about whether to stay at the hospital when the medical team recommended it.

And 16% of respondents said they know someone who has left the hospital against medical advice to go care for their pets.

“These patients are stressed already; how do you heal or accept staying in the hospital for treatment when you’re also worried about the welfare of your beloved pets?” said first author Carri Polick, R.N., a doctoral student at the U-M School of Nursing. “It can be hard if a patient doesn’t have a lot of social contacts or family members.”  “I’ve had patients with acute strokes explain to me that they needed to get home to their pets, even though it was in their best medical interest to be admitted or remain in the hospital.” Tiffany Braley, M.D., M.S.

Although social work is typically brought in to help patients come up with care plans for their pets, they may not be notified until several days into the hospitalization, typically when the situation is urgent, and are usually forced to turn to the patient’s social circle for help. Unfortunately, some patients do not have available social support, and there are limitations in what is available for assistance.

“We see a rising need for a formalized services to identify patients early in their course who need assistance with pet care, and a need to provide better resources, before it becomes a crisis and impacts their care or the welfare of their pets,” said Braley, the senior author and principal investigator.

The study team notes that, while this study is an important first step, the survey was small and included mostly women and white participants who live in nearby Washtenaw, Wayne and Oakland counties, which could indicate low estimations of the issue at large. To learn more about the overall scope and impact of pet care needs in a larger, more diverse group, the team is now studying people currently hospitalized or in the Emergency Department at Michigan Medicine to explore how pet care needs affect their hospital outcomes.

They’ve also started talking with potential local partners, including the Michigan Humane Society, to brainstorm what a future foster care collaboration could look like.

“This research is further evidence that pets are truly a part of the family and an important part of how and why we make decisions,” said Matt Pepper, the organization’s president and CEO. “Here at Michigan Humane, our work has taught us that people will forego their own health and safety for that of their pet. This study reinforces the need for communities to support families inclusive of the pet.”

Braley said a pilot program might start by focusing on a specific unit or patient population first – perhaps people needing inpatient rehabilitation, or parents of a child in the hospital who have an animal back at home. That way, the team could start helping people and their pets while they continue learning about the needs.

“Given the importance of pets to human health, follow-on studies are needed to explore how pet ownership impacts patients’ healthcare decision-making and outcomes,” Braley said. “If there is a link between pet ownership and adherence to medical treatments, I hope that early assessment of pet care needs and implementation of patient-centered methods to meet these needs will become standard of care for hospitalized patients.”

Additional authors include Jennifer W. Applebaum, M.S., Caitlin Hanna, Darnysus Jackson, II, M.S., Sophia Tsaras-Schumacher, LMSW, Rachel Hawkins, LMSW, Alan Conceicao, Louise M. O’Brien, Ph.D., M.S. and Ronald D. Chervin, M.D., M.S.

Paper cited: “The impact of pet care needs on medical decision-making among hospitalized patients: A cross-sectional analysis of patient experience,” Journal of Patient Experience. DOI: 10.1177/23743735211046089.

Source: University of Michigan Health

Cartilage Resurfacing Implant Reduces Pain, Restores Hip Joint Function in Dogs

Image by Chen Vision, licensed under CC BY-NC 2.0

A textile-based implant containing cartilage derived from stem cells reduced pain and restored hip joint function to baseline levels in a study of dogs with symptoms of moderate osteoarthritis. The study, led by researchers at North Carolina State University, Washington University in St. Louis and Cytex Therapeutics Inc., could be a significant first step toward preventative, less invasive joint resurfacing in dogs and humans.

In humans – and in dogs – a single, millimeter-thick layer of cartilage can mean the difference between an active lifestyle or painful osteoarthritis. That tiny cap of cartilage is what protects joint surfaces and allows the bones to glide over one another smoothly. Age or joint injury can cause the cartilage to degrade, leading to osteoarthritis and progressive joint pain.

“One of the holy grails of orthopedics is to replace cartilage, but there hasn’t been an effective way to do it,” says Duncan Lascelles, professor of surgery and translational pain research and management at NC State and co-corresponding author of the research. “Most of the focus is on replacing or restoring the cartilage surface with artificial materials, but regenerating cartilage isn’t possible right now. And many of the artificial products in use don’t integrate with the body.”

Farshid Guilak, the Mildred B. Simon Professor of Orthopedic Surgery at Washington University and Shriners Hospitals for Children, along with Bradley Estes and Frank Moutos, founded Cytex Therapeutics to develop an implant that could replace damaged or missing cartilage. The implant is made using a unique combination of manufacturing techniques that result in a part textile, part 3D-printed structure, which can be seeded with the patient’s own stem cells.

“Combining 3D printing with advanced textiles enabled us to engineer an implant that mimics the function of native, healthy tissues in the joint from day one after implantation,” Estes says. “We also designed it to dissolve over time so that, ultimately, joint function is transferred back to the patient’s own tissues during the healing process.”

The researchers designed a study to test the implant for resurfacing joints in dogs, a critical step in translating this technology into use for both canine and human patients.

In the study, cartilage was allowed to grow on the implant for several weeks before surgery. Then the implant was placed into the damaged area of the hip’s ball joint. Over time, the implant dissolved, ultimately leaving only the patient’s own natural tissue in the repaired hip joint.

The dogs in the study were divided into two groups – one which received the implant, and a control group which did not. Lascelles, NC State research associate Masataka Enomoto and their NC State colleagues performed the surgeries and measured subsequent joint pain and function in both groups.

Four months post-surgery, the group that received the cartilage implant had returned to baseline levels for both function and pain, while the control group never improved. The researchers also saw evidence that the implant had successfully integrated into the hip joints, effectively resurfacing them.

“What we saw is that with the implant these dogs were doing as well as or better than they would be after a total joint replacement,” Lascelles says.

“We were thrilled that the implant was so effective at restoring the activity levels of the animals,” Estes says. “After all, this is why patients go see their physicians – they want to be able to play tennis, play with their kids, and, in general, re-engage in a pain-free active lifestyle that had been taken away by arthritis.”

Lascelles hopes that the implant will address some of the issues involved with total joint replacements in young and active patients.

“There are significant drawbacks to total joint replacements in the young patient,” Lascelles says. “The surgery is more complicated, and the artificial joints are only good for a particular number of years until they must be replaced, often with poorer results each time.

“This procedure is less invasive, and the implant uses the body’s own cells and integrates into the damaged area with little danger of rejection. We believe that it is an early intervention that could be a major advance in postponing joint replacements for dogs and hopefully one day for humans.”

The work appears in Science Advances and was supported by Shriners Hospitals for Children, the Arthritis Foundation, the Nancy Taylor Foundation for Chronic Diseases, and the National Institutes of Health under grant numbers AR055042, AG46927, AG15768, AR74240, AR073752, and AR074992. Cytex Therapeutics has licensed the implant technology. Enomoto and Estes are co-first authors of the paper. Researchers from the Medical College of Wisconsin and Purdue University also contributed to the work.

Source: North Carolina State News

Dogs Tell the Difference between Intentional and Unintentional Action

A study published in Scientific Reports compared dogs’ spontaneous reactions to intentional and unintentional human behavior and found that dogs reacted differently depending on the condition.

Over our long shared history, dogs have developed a range of skills for bonding with human beings. Their ability to make sense of human actions, demonstrated by every “sit,” “lay down,” and “roll over,” is just one such skill. But whether dogs understand human intentions, or merely respond to outcomes, remains unclear. The ability to recognize another’s intentions – or at least conceive of them – is a basic component of Theory of Mind, the ability to attribute mental states to oneself and others, long regarded as uniquely human. Do dogs have this basic component of Theory of Mind, the ability to tell the difference between something done on purpose and something done by accident? 

To answer this question, a team of researchers in Germany conducted an experiment that examined how dogs reacted when food rewards were withheld, both intentionally and unintentionally. They found that dogs respond differently depending on whether the actions of the experimenter were intentional or unintentional. This, the researchers say, shows that dogs can distinguish between actions that were done on purpose or accidentally. 

To reach their conclusions, the researchers conducted an experiment using the “unable vs. unwilling” paradigm. This works by examining whether test subjects react differently towards a human experimenter who either intentionally (the unwilling condition) or unintentionally (the unable condition) withholds rewards from them. Despite being an established paradigm in studies of human and animal cognition, the unable vs. unwilling paradigm had never been previously used to investigate dogs. 

Dogs were fed through the gap before the experimenter started to withhold the reward intentionally or unintentionally
© Josepha Erlacher

The experiment was conducted with 51 dogs, each of which was tested under three conditions. In each condition, the dog was separated from the human tester by a transparent barrier. The basic situation was that the experimenter fed the dog pieces of dog food through a gap in the barrier. In the “unwilling” condition, the experimenter suddenly withdrew the reward through the gap in the barrier and placed it in front of herself. In the “unable-clumsy” condition, the experimenter brought the reward to the gap in the barrier and “tried” to pass it through the gap but then “accidentally” dropped it. In the “unable-blocked” condition, the experimenter again tried to give the dog a reward, but was unable to because the gap in the barrier was blocked. In all conditions, the reward remained on the tester’s side of the barrier.

“If dogs are indeed able to ascribe intention-in-action to humans,” says Dr. Juliane Bräuer, “we would expect them to show different reactions in the unwilling condition compared to the two unable conditions. As it turns out, this is exactly what we observed.”

The primary behaviour measured by the researchers was the time dogs waited before approaching the reward they were denied. The researchers predicted that, if dogs are able to identify human intentions, they would wait longer before approaching the reward in the unwilling condition, where they were not supposed to have the reward, than in the two unable conditions in which the reward was, in fact, meant for them. 

Not only did the dogs wait longer in the unwilling condition than in the unable conditions, they were also more likely to sit or lie down – actions often interpreted as appeasing behaviours – and stop wagging their tails. 

“The dogs in our study clearly behaved differently depending on whether the actions of a human experimenter were intentional or unintentional,” says Britta Schünemann, the first author of the study. “This suggests that dogs may indeed be able to identify humans’ intention-in-action,” adds Hannes Rakoczy from the University of Göttingen.

The team acknowledges that their findings may be met with scepticism and that further study is needed to address alternative explanations, such as behavioural cues on the part of experimenters or knowledge transfer from prior dog training. 

“Nevertheless,” the paper concludes, “the findings present important initial evidence that dogs may have at least one aspect of Theory of Mind: The capacity to recognize intention-in-action.”

Source: Max Planck Institute for the Science of Human History

Dogs may not return their owners’ good deeds

Domestic dogs show many adaptations to living closely with humans, but they do not seem to reciprocate food-giving, according to an Austrian study published in the open-access journal PLOS ONE

Photo: chalabala 123RF

Researchers at the University of Veterinary Medicine in Vienna trained 37 domestic dogs to operate a food dispenser by pressing a button, before separating the button and dispenser in separate enclosures. 

In the first stage, dogs were paired with two unfamiliar humans one at a time. One human partner was helpful—pressing their button to dispense food in the dog’s enclosure—and one was unhelpful.

The researchers also reversed the set-up, with a button in the dog’s enclosure that operated a food dispenser in the human’s enclosure. 

They found no significant differences in the dogs’ tendency to press the button for helpful or unhelpful human partners, and the human’s behaviour in the first stage did not affect the dog’s behaviour towards them in free interaction sessions after the trials.

Previous studies have demonstrated that dogs are capable of directing helpful behaviours towards other dogs that have helped them previously—a behaviour known as reciprocal altruism—and research suggests dogs are also able to distinguish between cooperative and uncooperative humans. 

However, the present study failed to find evidence that dogs can combine these capabilities to reciprocate help from humans. This finding may reflect a lack of ability or inclination among dogs to reciprocate, or the experimental design may not have detected it.

Source: Vet Practice magazine

Genetic enigma solved: Inheritance of coat color patterns in dogs

An international team of researchers including scientists from the Institute of Genetics of the University of Bern has unraveled the enigma of inheritance of coat color patterns in dogs. The researchers discovered that a genetic variant responsible for a very light coat in dogs and wolves originated more than two million years ago in a now extinct relative of the modern wolf.

Wolf (stock image).
Credit: © Matthieu / stock.adobe.com

The inheritance of several coat color patterns in dogs has been controversially debated for decades. Researchers including Tosso Leeb from the Institute of Genetics of the University of Bern have now finally been able to solve the puzzle. Not only did they clarify how the coat color patterns are genetically controlled, but the researchers also discovered that the light coat color in white arctic wolves and many modern dogs is due to a genetic variant originating in a species that went extinct a long time ago. The study has just been published in the scientific journal Nature Ecology and Evolution.

Two pigments and a “switch” for all coat colors

Wolves and dogs can make two different types of pigment, the black one, called eumelanin and the yellow, pheomelanin. A precisely regulated production of these two pigments at the right time and at the right place on the body gives rise to very different coat color patterns. Prior to the study, four different patterns had been recognized in dogs and several genetic variants had been theorized which cause these patterns. However, commercial genetic testing of these variants in many thousands of dogs yielded conflicting results, indicating that the existing knowledge on the inheritance of coat color patterns was incomplete and not entirely correct.

During the formation of coat color, the so-called agouti signaling protein represents the body’s main switch for the production of yellow pheomelanin. If the agouti signaling protein is present, the pigment producing cells will synthesize yellow pheomelanin. If no agouti signaling protein is present, black eumelanin will be formed. “We realized early on that the causative genetic variants have to be regulatory variants which modulate the rate of protein production and lead to higher or lower amounts of agouti signal protein”, Tosso Leeb explains.

Five instead of four distinct coat color patterns

The gene for agouti signaling protein has several initiation sites for reading the genetic information, which are called promoters. Dogs, on the one hand, have a ventral promoter, which is responsible for the production of agouti signaling protein at the belly. On the other hand, dogs have an additional hair cycle-specific promoter that mediates the production of agouti signaling protein during specific stages of hair growth and enables the formation of banded hair.

For the first time, the researchers characterized these two promoters in detail, in hundreds of dogs. They discovered two variants of the ventral promoter. One of the variants conveys the production of normal amounts of agouti signaling protein. The other variant has higher activity and causes the production of an increased amount of agouti signaling protein. The researchers even identified three different variants of the hair cycle-specific promoter. Starting with these variants at the individual promoters, the researchers identified a total of five different combinations, which cause different coat color patterns in dogs. “The textbooks have to be rewritten as there are five instead of the previously accepted four different patterns in dogs”, Leeb says.

Unexpected insights on the evolution of wolves

As many genomes from wolves of different regions on earth have become publicly available, the researchers further investigated whether the identified genetic variants also exist in wolves. These analyses demonstrated that the variants for overactive ventral and hair cycle-specific promoters were already present in wolves prior to the domestication of modern dogs, which started approximately 40,000 years ago. Most likely, these genetic variants facilitated adaptation of wolves with a lighter coat color to snow-rich environments during past ice ages. Today, the completely white arctic wolves and the light colored wolves in the Himalaya still carry these genetic variants.

Further comparisons of the gene sequences with other species of the canidae family yielded very surprising results. The researchers were able to show that the overactive variant of the hair cycle-specific promoter in light-colored dogs and wolves shared more similarities with very distantly related species such as the golden jackal or the coyote than with the European grey wolf.

“The only plausible explanation for this unexpected finding is an ancient origin of this variant, more than two million years ago, in a now extinct relative of wolves”, Leeb says. The gene segment must have been introgressed more than two million years ago into wolves by hybridization events with this now extinct relative of wolves. Thus, a small piece of DNA from this extinct species is still found today in yellow dogs and white arctic wolves. “This is reminiscent of the spectacular finding that modern humans carry a small proportion of DNA in their genomes from the now extinct Neandertals”, Leeb adds.

Source: University of Bern

Restless nights: shelter housed dogs need days to adapt to new surroundings

Every year, thousands of dogs end up in a shelter in the Netherlands. Experts expect an increase in this number in the upcoming period, when people go back to the office after working from home during the corona crisis.

Despite the good care of staff and volunteers, the shelter can be a turbulent experience for dogs. Researchers at Utrecht University investigated if dogs can adapt to their new environment based on their nocturnal activity. 

Photo: Janneke van der Laan

Janneke van der Laan and fellow researchers from Utrecht University’s Faculty of Veterinary Medicine compared the nocturnal activity of 29 shelter dogs and 29 pet dogs in their own homes – similar in breed, age and sex – with the help of night cameras and a small activity tracker on their collar.

They found that shelter dogs rest much less at night than pet dogs, especially during the first two nights in the shelter. This restlessness did decrease over time, but even after twelve days in the shelter, the dogs still rested less at night than the pet dogs. 

“We also saw this restlessness in hormone measurements in the urine of shelter dogs” says Janneke van der Laan. Shelter dogs had higher values of the stress hormone cortisol in their urine than pet dogs, especially during the first two days but also after twelve days. It was also striking that smaller shelter dogs, for instance Shi Tzu’s and Chihuahua’s, were more restless during the first two nights than larger shelter dogs, and they also had higher cortisol values.

The researchers found big differences between individual dogs: some were already quite calm during the first night in the shelter, while others barely slept for a few nights. “It seems that dogs need at least two days, but often longer to get used to their new environment, in this case the shelter,” Van der Laan explains. “Humans usually also sleep less good during the first night in a new environment, for example at the beginning of a vacation.” 

“With our follow-up research we will zoom in even further on the welfare of dogs in shelters. But our current findings already show that it is important to pay close attention to dogs that are unable to rest properly after several nights. The shelter staff may already be able to help these dogs by for example moving them to a less busy spot in the shelter.”

Publication

“Restless nights? Nocturnal activity as a useful indicator of adaptability of shelter housed dogs”, Applied Animal Behaviour Science. doi.org/10.1016/j.applanim.2021.105377

Source: Utrecht University