Category Archives: research

The evolution of puppy dog eyes

Dogs have evolved new muscles around the eyes to better communicate with humans. New research comparing the anatomy and behavior of dogs and wolves suggests dogs’ facial anatomy has changed over thousands of years specifically to allow them to better communicate with humans.

Puppy dog eyes

In the first detailed analysis comparing the anatomy and behavior of dogs and wolves, researchers found that the facial musculature of both species was similar, except above the eyes. Dogs have a small muscle, which allows them to intensely raise their inner eyebrow, which wolves do not.

The authors suggest that the inner eyebrow raising movement triggers a nurturing response in humans because it makes the dogs’ eyes appear larger, more infant like and also resembles a movement humans produce when they are sad.

The research team, led by comparative psychologist Dr Juliane Kaminski, at the University of Portsmouth, included a team of behavioural and anatomical experts in the UK and USA.

It is published in PNAS (Proceedings of the National Academy of Sciences).

Dr Kaminski said: “The evidence is compelling that dogs developed a muscle to raise the inner eyebrow after they were domesticated from wolves.

“We also studied dogs’ and wolves’ behavior, and when exposed to a human for two minutes, dogs raised their inner eyebrows more and at higher intensities than wolves.

“The findings suggest that expressive eyebrows in dogs may be a result of humans unconscious preferences that influenced selection during domestication. When dogs make the movement, it seems to elicit a strong desire in humans to look after them. This would give dogs, that move their eyebrows more, a selection advantage over others and reinforce the ‘puppy dog eyes’ trait for future generations.”

Dr Kaminski’s previous research showed dogs moved their eyebrows significantly more when humans were looking at them compared to when they were not looking at them.

She said: “The AU101 movement is significant in the human-dog bond because it might elicit a caring response from humans but also might create the illusion of human-like communication.”

Lead anatomist Professor Anne Burrows, at Duquesne University, Pittsburgh, USA, co-author of the paper, said: “To determine whether this eyebrow movement is a result of evolution, we compared the facial anatomy and behaviour of these two species and found the muscle that allows for the eyebrow raise in dogs was, in wolves, a scant, irregular cluster of fibres.

“The raised inner eyebrow movement in dogs is driven by a muscle which doesn’t consistently exist in their closest living relative, the wolf.

“This is a striking difference for species separated only 33,000 years ago and we think that the remarkably fast facial muscular changes can be directly linked to dogs’ enhanced social interaction with humans.”

Dr Kaminski and co-author, evolutionary psychologist Professor Bridget Waller, also at the University of Portsmouth, previously mapped the facial muscular structure of dogs, naming the movement responsible for a raised inner eyebrow the Action Unit (AU) 101.

Professor Waller said: “This movement makes a dogs’ eyes appear larger, giving them a childlike appearance. It could also mimic the facial movement humans make when they’re sad.

“Our findings show how important faces can be in capturing our attention, and how powerful facial expression can be in social interaction.”

Co-author and anatomist Adam Hartstone-Rose, at North Carolina State University, USA, said: “These muscles are so thin that you can literally see through them – and yet the movement that they allow seems to have such a powerful effect that it appears to have been under substantial evolutionary pressure. It is really remarkable that these simple differences in facial expression may have helped define the relationship between early dogs and humans.”

Co-author Rui Diogo, an anatomist at Howard University, Washington DC, USA, said: “I must admit that I was surprised to see the results myself because the gross anatomy of muscles is normally very slow to change in evolution, and this happened very fast indeed, in just some dozens of thousands of years.”

Soft tissue, including muscle, doesn’t tend to survive in the fossil record, making the study of this type of evolution harder.

The only dog species in the study that did not have the muscle was the Siberian husky, which is among more ancient dog breeds.

An alternative reason for the human-dog bond could be that humans have a preference for other individuals which have whites in the eye and that intense AU 101 movements exposes the white part of the dogs eyes.

It is not known why or precisely when humans first brought wolves in from the cold and the evolution from wolf to dog began, but this research helps us understand some of the likely mechanisms underlying dog domestication.

Source:  University of Portsmouth

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Sleeping with your dog – yes or no?

USA bedding manufacturer, Casper, has produced a useful infographic about the research into the benefits of sleeping with your dog (and a few tips about when you probably shouldn’t).

Reasons to sleep with your dog

Source:  Casper.com

“Moral distress” in the veterinary profession

This study’s lead author is Dr Lisa Moses.  Back in 2012, Lisa allowed me to follow her at Angell Animal Medical Center as she worked with dogs in her pain management clinic.

Although no one will argue about the rates of suicide in the veterinary profession, I’d also suggest that complementary practitioners also suffer from a level of moral distress – I’ve seen dogs that could have significant improvement but their owners are prevented from pursuing full therapy for a variety of reasons.  My very first tutor in canine massage prepared us by saying, “you will meet clients that don’t share your values or moral compass.”

Kathleen Crisley, Fear-Free certified professional and specialist in dog massage, rehabilitation and nutrition/food therapy, The Balanced Dog, Christchurch, New Zealand


In some ways, it can be harder to be a doctor of animals than a doctor of humans.

“We are in the really unenviable, and really difficult, position of caring for patients maybe for their entire lives, developing our own relationships with those animals — and then being asked to kill them,” says Dr. Lisa Moses, a veterinarian at the Massachusetts Society for the Prevention of Cruelty to Animals-Angell Animal Medical Center and a bioethicist at Harvard Medical School.

Dr Lisa Moses

Dr Lisa Moses courtesy of MSPCA – Angell

She’s the lead author of a study published in the Journal of Veterinary Internal Medicine about “moral distress” among veterinarians. The survey of more than 800 vets found that most feel ethical qualms — at least sometimes — about what pet owners ask them to do. And that takes a toll on their mental health.

Dr. Virginia Sinnott-Stutzman is all too familiar with the results. As a senior staff veterinarian in emergency and critical care at Angell, she sees a lot of very sick animals — and quite a few decisions by owners that trouble her

Sometimes, owners elect to have their pets put to sleep because they can’t or won’t pay for treatment, she says. Or the opposite, “where we know in our heart of hearts that there is no hope to save the animal, or that the animal is suffering and the owners have a set of beliefs that make them want to keep going.”

Distress around choices such as those is pervasive among vets, Moses and her colleagues found. For example, 69 percent said they had felt moderate to severe distress about not being able to give animals what they thought was the right care. Almost two-thirds were bothered by inappropriate requests for euthanasia.

The study’s senior author, Cambridge Health Alliance psychiatrist and Harvard bioethicist J. Wesley Boyd, sees a connection between the study’s findings and daunting statistics about veterinarians’ suicide rates: “My assumption,” he says, “is that the findings from our survey are definitely part of, or even the majority of, the reason why veterinarians have higher-than-average suicide rates.”

And Moses says that while euthanizing an animal is often the right thing to do to end suffering, that doesn’t make it easy.

“I want to make a plea to the pet-owning public to understand that, no matter what you think, odds are the person who’s trying to help you take care of your animal has pretty strong feelings about how important that is,” she says. “And they feel it.”

The study’s authors are calling for better training — in veterinary school and beyond — on self-care and how to cope with moral distress and ethical conflict.

Sinnott-Stutzman defines moral distress as the feeling when the vet determines an optimal treatment course but is blocked from carrying it out — whether because of money, or an owner’s beliefs, or rules about, say, dogs that bite.

“The most poignant example is when a young dog has a fracture — so a totally fixable, non-life-threatening problem,” she says. But an owner neither wants to pay for a proper fix nor have a three-legged dog, and opts for euthanasia instead.

“That’s a really tough thing to go through,” she says. It’s also particularly hard, she says, when owners, caught up in their grief, project their anger onto the vet. “So in this example,” she says, they might say, ” ‘We have to kill our dog because you’re all about the money,’ which is of course not the case.”

In her 15 years doing emergency and critical care, Sinnott-Stutzman says, she has changed how she copes with moral distress. In the past, she would mainly talk tough cases through with colleagues. Now, she often tries to refocus her mind — meditate, take a walk, think about her kids. She might share an experience with her husband — who will focus on her feelings — rather than a colleague, who is likelier to focus on the medical aspects.

She strongly endorses the study authors’ call for better training for vets in how to handle moral distress. Everything she has learned about coping has come from mentors and friends outside the veterinary profession, she says, and “it absolutely needs to be part of how we teach vets.”

Source:  WBUR

Owning a dog is influenced by our genetic make-up

A team of Swedish and British scientists have studied the heritability of dog ownership using information from 35,035 twin pairs from the Swedish Twin Registry. The results indicate that an individual’s genetic make-up has a great influence on whether they choose to acquire a dog. Genes appear to account for more than half of the difference in dog ownership.

Dog ownership

“Perhaps some people have a higher innate propensity to care for a pet than others” Photograph: Mikael Wallerstedt

Dogs were the first domesticated animal and have had a close relationship with humans for at least 15,000 years. Today, dogs are common pets in our society and are considered to increase the well-being and health of their owners. The team compared the genetic make-up of twins (using the Swedish Twin Registry – the largest of its kind in the world) with dog ownership. The results are published for the first time in Scientific Reports. The goal was to determine whether dog ownership has a heritable component.

“We were surprised to see that a person’s genetic make-up appears to be a significant influence in whether they own a dog. As such, these findings have major implications in several different fields related to understanding dog-human interaction throughout history and in modern times. Although dogs and other pets are common household members across the globe, little is known how they impact our daily life and health. Perhaps some people have a higher innate propensity to care for a pet than others,” says Tove Fall, lead author of the study, and Professor in Molecular Epidemiology at the Department of Medical Sciences and the Science for Life Laboratory, Uppsala University.

Health benefits of owning a dog

Carri Westgarth, Lecturer in Human-Animal interaction at the University of Liverpool and co-author of the study, adds: “These findings are important as they suggest that supposed health benefits of owning a dog reported in some studies may be partly explained by different genetics of the people studied”.

Studying twins is a well-known method for disentangling the influences of environment and genes on our biology and behaviour. Because identical twins share their entire genome, and non-identical twins on average share only half of the genetic variation, comparisons of the within-pair concordance of dog ownership between groups can reveal whether genetics play a role in owning a dog.

Genetics play a major role

The researchers found concordance rates of dog ownership to be much larger in identical twins than in non-identical ones – supporting the view that genetics indeed plays a major role in the choice of owning a dog.

“These kind of twin studies cannot tell us exactly which genes are involved, but at least demonstrate for the first time that genetics and environment play about equal roles in determining dog ownership. The next obvious step is to try to identify which genetic variants affect this choice and how they relate to personality traits and other factors such as allergy” says Patrik Magnusson, senior author of the study and Associate Professor in Epidemiology at the Department of Medical Epidemiology and Biostatistics at Karolinska Insitutet, Sweden and Head of the Swedish Twin Registry.

“The study has major implications for understanding the deep and enigmatic history of dog domestication” says zooarchaeologist and co-author of the study Keith Dobney, Chair of Human Palaeoecology in the Department of Archaeology, Classics and Egyptology at the University of Liverpool. “Decades of archaeological research have helped us construct a better picture of where and when dogs entered into the human world, but modern and ancient genetic data are now allowing us to directly explore why and how?”

Source:  Uppsala University

Dog pee on the sidewalk does more than just piss off your neighbors

Note from DoggyMom I follow all types of research.  But some – like this one – needs to be put into a larger context.  Urban cities have a lot of runoff thanks to all the hard surfaces including roads and sidewalks.  Urban designers look to institute green spaces to help with infiltration of water into soils and decrease runoff, which can be particularly helpful in high volume, storm events which overwhelm stormwater systems.

Urban runoff has a lot of contaminants from the oils, dust and debris of modern life.  All meat-eating animals have high nitrogen in their urine – and that’s why countries like NZ have issues with groundwater quality because of the number of cows that are left to graze and urinate on open pastures.  So of course dogs will have an impact on the soil quality and runoff in the very limited areas of green that they have to use in urban cities.  The solution?  Well, in my opinion, it’s partly an argument for creating more green space.


Nobody knows just how many dogs there are in the United States, but there are plenty—and many of them live (and pee) in human cities. Turns out, canine bathroom breaks may have more of an impact on the environment than you might think.

In a new study, a team of Columbia University undergraduate and graduate researchers led by ecologist Krista McGuire looked at the impact of pee on the urban soil microbiome. They found evidence that the nitrogen content and low pH of the urine can make city soil both harder and less absorbent of rainwater, while making the soil microbiome less diverse.

Your very good boy

The project was born out of McGuire’s observations with colleagues during other research on green infrastructure in NYC. In sites like unfenced tree pits, “the soils seemed barren, compacted, and the water from rainfall didn’t seem to penetrate very well,” she says.

The team suspected soil’s characteristics had something to do with all the dogs that urinated on those sites, so they designed an experiment to check. “We obtained soil from the city environment,” says McGuire, along with one species of commonly-used plant from the same nursery the city uses.

Both of these factors replicate what’s used out in the real world. Getting actual dog pee turned out to be harder. They approached animal shelters, which mostly turned them away, while the one shelter that acquiesced didn’t yield enough pee—the experiment required a whopping 40 gallons.

“Despite visiting the shelter twice a week for a couple months, less than 40mL [1.35 oz] of urine was collected due to difficulty in predicting when the dogs will urinate and the dogs’ refusal to continue urinating when a collecting bowl was brought near them as they were about to urinate,” the paper states.

“Ultimately, we decided to use coyote urine since coyotes are very closely related to domestic dogs, and their urine is commercially available,” McGuire says. If you’re not a gardener looking to repel deer from your tulips, you may not be aware of this, but yes, you can buy 40 gallons of coyote pee pretty easily.  (Note from DoggyMom:  Coyotes are kept in captivity and their urine is collected through drainage systems.  Some say that the income from the coyote urine farms help to support other conservation efforts.   I will need to research this further.)

Over the course of a month, they ran a greenhouse experiment, watering the plants at regular intervals with either straight water or water mixed with urine at different concentrations. They checked the soil each week. The results were dramatic: the bacterial community diversity decreased by up to a third during the experiment, and the kinds of bacteria in the microbiome changed. Meanwhile, the “runoff” from pots increased significantly, signifying that the soil was becoming less absorbent.

Outside the lab (say, outside your door), “a variety of different events can affect the impact of urine deposition,” says Gary King, a Louisiana State University biology professor who studies urban microbiomes. This experiment doesn’t address those factors—like, what if it’s raining, or what if some other pollutant has recently entered the soil?

But the results point to an important direction of research, he says. “There is a huge gap in our knowledge about basic microbial functions in the soils that are part of the system in our own built environment.”

That’s a serious problem, because soils help keep a city running. Things like street trees and planted medians aren’t just there to make downtown look good. Cities are mostly built on hard surfaces like concrete and asphalt, which don’t absorb water and allow it to enter the soil, so the sewer system works to keep water off the roads and out of your basement. But sometimes, it rains too much for this system. That’s where what’s known as “green infrastructure” comes in, by helping to absorb all the extra water. Otherwise, says McGuire, “What happens is that the stormwater combines with raw sewage in these below-ground piping systems. Past a certain threshold, it gets spewed out into local waterways.”

To keep this from happening, cities like New York are investing lots of money in building and maintaining green infrastructure, from street trees to deliberately designed water capture landscapes called “bioswales.” But as this research indicates, our furry friends’ bathroom breaks may be making these interventions less effective.

Journal citation:  Evaluating the effects of canine urine on urban soil microbial communities

Source:   Popular Science

Mutation makes bulldogs and Norwich terriers more susceptible to breathing problems

The discovery of a new mutation associated with breathing difficulties in popular dog breeds suggests that shortened skulls causing flat faces is not the only factor that contributes to the condition, but that swelling around the airways from edema may also play a role. Jeffrey Schoenebeck of the University of Edinburgh and colleagues report these findings in a new study published 9th May 2019 in PLOS Genetics.

Respiratory diseases are prevalent across dog breeds, particularly in brachycephalic breeds such as the Bulldog and French bulldog. The flat facial conformation of these breeds has long been assumed to be the major predisposing factor, however, the underlying genetics of their respiratory condition has never been elucidated.

Upper Airway Syndrome

The research team became interested in the Norwich Terrier, a breed presenting with many of the same respiratory disease symptoms as the Bulldog. A distinction, however, is that the Norwich terrier is not considered to be a brachycephalic breed and so presented an opportunity to dissociate respiratory disease from head conformation.

The researchers performed a genome-wide association analysis for respiratory disease severity in the Norwich Terrier and resolved an association on chromosome 13 to a missense mutation in ADAMTS3. Variants in this gene were previously shown to cause an oedematous phenotype–a disease characteristic in the airways of affected Norwich Terriers and brachycephalic dogs alike. The researchers screened over 100 breeds for the ADAMTS3 variant and found that it is enriched in the Norwich Terrier, Bulldog and French Bulldog. This discovery changes how we view respiratory disease predisposition in the dog, offers potential genetic screens and highlights a new biological function for ADAMTS3.

The study presents a new way of looking at these respiratory diseases in dogs, where fluid retention in the tissue that lines the airways makes it more likely that dogs with the mutation will develop breathing obstructions. “We conclude that there are additional genetic risk factors, that if inherited, will likely lead to airway disease in dogs regardless of their face shape,” stated author Jeffrey Schoenebeck. “The challenge ahead is to integrate these ideas, and implement sensible breeding practices and treatments that consider various health risks including those presented by the mutation of ADAMTS3.”

If scientists develop a test for this mutation, then dog breeders can develop better breeding practices to avoid passing on the faulty gene. Additionally, screening for the mutation may help veterinarians identify dogs which are at risk of UAS, and in particular identify the dogs at risk of swelling of their airways after surgical treatment, which is a common, life-threatening post-operative complication.

Sources:  Science Daily and PLOS Genetics

Study shows dogs can accurately sniff out cancer in blood

Dogs have smell receptors 10,000 times more accurate than humans’, making them highly sensitive to odors we can’t perceive. A new study has shown that dogs can use their highly evolved sense of smell to pick out blood samples from people with cancer with almost 97 percent accuracy. The results could lead to new cancer-screening approaches that are inexpensive and accurate without being invasive.

Beagle sniffing cancer

A new study has shown that dogs can use their highly evolved sense of smell to pick out blood samples from people with cancer with almost 97 percent accuracy. Photo by: BioScentDx

“Although there is currently no cure for cancer, early detection offers the best hope of survival,” said Heather Junqueira, who is lead researcher at BioScentDx and performed the study. “A highly sensitive test for detecting cancer could potentially save thousands of lives and change the way the disease is treated.”

Junqueira will present this research at the American Society for Biochemistry and Molecular Biology annual meeting during the 2019 Experimental Biology meeting to be held April 6-9 2019 in Orlando, Fla.

For the new study, Junqueira and her colleagues used a form of clicker training to teach four beagles to distinguish between normal blood serum and samples from patients with malignant lung cancer. Although one beagle — aptly named Snuggles — was unmotivated to perform, the other three dogs correctly identified lung cancer samples 96.7 percent of the time and normal samples 97.5 percent of the time.

“This work is very exciting because it paves the way for further research along two paths, both of which could lead to new cancer-detection tools,” said Junqueira. “One is using canine scent detection as a screening method for cancers, and the other would be to determine the biologic compounds the dogs detect and then design cancer-screening tests based on those compounds.”

BioScentDx plans to use canine scent detection to develop a non-invasive way of screening for cancer and other life-threatening diseases. As a next step, the company launched a breast cancer study in November in which participants donate samples of their breath for screening by trained cancer-sniffing dogs. The researchers also plan to separate the samples into their chemical components and present these to the dogs to isolate the substances causing the odor that the dogs detect.

About Experimental Biology 2019

Experimental Biology is an annual meeting comprised of more than 14,000 scientists and exhibitors from five host societies and multiple guest societies. With a mission to share the newest scientific concepts and research findings shaping clinical advances, the meeting offers an unparalleled opportunity for exchange among scientists from across the United States and the world who represent dozens of scientific areas, from laboratory to translational to clinical research.

Source:  EurekAlert! media statement