Category Archives: research

Your dog’s water bowl: microbiology

This research was delivered to the 69th Annual Meeting of the European Federation of Animal Science meeting in August 2018.

It’s important to clean your dog’s water bowl regularly – don’t be tempted to simply keep filling it up because bacteria grows on the sides of the bowl.  (Run your finger over it and you’ll probably feel a slippery surface – that’s called biofilm)

I personally like stainless steel bowls because they can be washed in very hot water in the dishwasher and because they are durable and recyclable.

Dog water bowl


The number of pet dogs (Canis lupus familiaris) in the common household is continually rising. The increasingly close contact between humans and cohabitant pets is leading to concerns regarding bacterial transmission of zoonoses. The dog water bowl has been identified as the third most contaminated item within the household, suggesting that it is able to act as a fomite for bacterial transmission, particularly where young or immunocompromised individuals are present.

Studies in livestock have identified that water trough construction material influences bacterial count; however no similar research has been conducted for dog water bowls.

The objectives of the current study were to identify which dog bowl material, plastic, ceramic or stainless steel, harbours the most bacteria over a 14 day period and whether the species identified varies between bowl materials. The study took place over 6 weeks. A sample of 6, medium sized (10-25kg) dogs, aged 2-7 (mean= 3.8 ± 1.95), was used. All dogs were clinically healthy, housed individually and located within a rural environment. All bowls were purchased brand new and sterilised prior to a two week sampling period.

On day 0, day 7 and day 14 swabs were taken from each bowl and 10-fold serial dilutions were conducted on blood agar. The cultured bacteria were subjected to biochemical testing and the most prominent bacteria from day 14 were further identified using PCR. A significant difference was identified for all bowl materials when comparing total CFU/ml between day 0 and day 7 and day 0 and day 14 (p<0.05). No significant difference was identified between total CFU/ml and bowl material (P>0.05), however descriptive statistics suggest that the plastic bowl material maintains the highest bacterial count after 14 days.

Several medically important bacteria were identified from the bowls, including MRSA and Salmonella, with the majority of species being identified from the ceramic bowl. This could suggest that harmful bacteria may be able to develop biofilms more successfully on ceramic materials. Further research is required to identify the most suitable or alternative materials for dog water bowls.

Source: Microbiological Assessment of Canine Drinking Water and the Impact of Bowl Construction Material

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A ‘Robo-Nose’ Could Give K-9 Officers a Break

Robonose golden retriever

Golden retriever Rudy, wearing military dog tags and a U.S. flag, is being trained by the U.S. Army to use his amazing nose to find human remains. (Army photo)

Every day, thousands of trained K9 dogs sniff out narcotics, explosives and missing people across the United States. These dogs are invaluable for security, but they’re also very expensive and they can get tired.

Duke researchers have taken the first steps toward building an artificial “robot nose” device made from living mouse cells that officers could use instead of dogs.

The researchers have developed a prototype based on odor receptors grown from the genes of mice that respond to target odors, including the smells of cocaine and explosives. Their work appeared earlier this month in Nature Communications.

It turns out, there are a couple of very big differences between testing things in a lab dish and testing them in an actual nose.

“This idea of an artificial nose has been present for a long time,” said senior study author Hiroaki Matsunami, a professor of molecular genetics and microbiology in the Duke School of Medicine. “The receptors were identified in the 1990s, but there are significant technical hurdles to produce all these receptors and monitor the activity so that we can use that in an artificial device.”

“E-noses” that exist now use various chemical compounds to detect smells instead of receptor stem cells, Matsunami said. He said those devices are “not as good as a trained dog.”

“The idea is that by using the actual, living receptors, maybe we can develop a device similar to animals,” Matsunami said. “Nobody has achieved that yet, but this study is moving toward that goal.”

Human, dog and mouse genomes contain around 20,000 genes, which contain instructions to create proteins that smell, taste, feel, move and do everything that our bodies do. About 5 percent of mouse genes have been identified as instructions to make odor receptors, Matsunami said. In contrast, humans only use about 2 percent of their genes to make odor receptors.

“These animals invest a lot of resources for this purpose,” Matsunami said. “Mice and rats are very good smellers; we just don’t use mice for detecting explosives in real life. There are some practical problems to do that.”

The first step of the study was to identify the best odor receptors to respond to target odors like cocaine or marijuana.

The researchers created a liquid medium primed with molecules that could light up from reactions. Next they copied about 80 percent of the odor receptors from mice, and mixed those receptors with seven target odor chemicals in the medium.

They measured the resulting luminescence and chose the best-performing odor receptors for the second part of the study, which monitored receptor activation in real time.

Previous research had done this by exposing selected receptors to odor chemicals in a liquid. But there are several differences between the petri dish and the nose. For one, we rarely submerge our noses into liquid baths of odor chemicals. Instead, our noses detect smells from wafting perfumes or stenches borne on the air. And our noses are full of mucus.

So, for the second half of the study, which was supported by the National Institute of Health grants DC014423 and DC016224 and the Defense Advanced Research Project Agency RealNose Project, they attempted to mimic how we use our noses by exposing odorants to vapors and a few enzymes.

The researchers tested the receptors they had identified against two odor vapors for this study.

“We only tested two of them in the paper, but it’s showing the proof of principle of how it can be used,” Matsunami said.

The researchers hope they can fine-tune the device to test all receptors against many different smells.

“We have a panel of receptors so we can monitor how different receptors respond differently to various smells, including ones that are similar to each other in chemical structure or ones that might be related to real-world use, like something associated to explosives or drugs,” Matsunami said.

The researchers also tested various enzymes that one might find in mucus to see how they aided or impeded reactions. This process is more true-to-life than vapor molecules directly interacting with odor receptors.

“You’d think when we smell a chemical, the chemical would bind to the chemical receptor in the nose, but actually it’s not so simple,” Matsunami said. “When the chemical dissolves in the nasal mucus before binding to the receptor, it might be converted to another chemical by enzymes in the nasal mucus.”

Mucus is an unknown frontier in understanding how we smell. Reconstructing the key components of nasal mucus may be the next step toward building an artificial nose, according to the paper.

“It’s not like our paper will be immediately applied to a portable device used in the airport soon, but this is an important step forward to show that it is possible,” Matsunami said. “We can more clearly see what kind of hurdles to pass in order for the community to create such a device.”

Three of the authors have filed a patent application for the work.

Source:  Duke University

Dogs know when they don’t know

When they don’t have enough information to make an accurate decision, dogs will search for more – similarly to chimpanzees and humans.

Researchers at the DogStudies lab at the Max Planck Institute for the Science of Human History have shown that dogs possess some “metacognitive” abilities – specifically, they are aware of when they do not have enough information to solve a problem and will actively seek more information, similarly to primates. To investigate this, the researchers created a test in which dogs had to find a reward – a toy or food – behind one of two fences. They found that the dogs looked for additional information significantly more often when they had not seen where the reward was hidden.

Metacognition study

In this study, dogs showed some of the signs of metacognition, specifically that they searched for more information when they had not seen where a reward was placed. © Juliane Bräuer

In the field of comparative psychology, researchers study animals in order to learn about the evolution of various traits and what this can tell us about ourselves. At the DogStudies lab at the Max Planck Institute for the Science of Human History, project leader Juliane Bräuer studies dogs to make these comparisons. In a recent study published in the journal Learning & Behavior, Bräuer and colleague Julia Belger, now of the Max Planck Institute for Human Cognitive and Brain Sciences, explore whether dogs have metacognitive abilities – sometimes described as the ability to “know what one knows” – and in particular whether they are aware of what information they have learned and whether they need more information.

To test this, the researchers designed an apparatus involving two V-shaped fences. A reward, either food or a toy, would be placed by one researcher behind one of the two fences while another researcher held the dog. In some cases, the dog could see where the reward was placed, while in others the dog could not. The researchers then analyzed how frequently the dogs looked through a gap in the fence before choosing an option. The question was whether, like chimps and humans, the dog would “check” through the gap when he or she had not seen where the reward was placed. This would indicate that the dog was aware that he or she did not know where the reward was – a metacognitive ability – and would try to get more information before choosing a fence.

Experiment set up

The overall set-up of the experiment, showing the two V-shaped fences, the experimenter who places the reward, the experimenter holding the dog, and the dog in starting position, without a curtain to block the view. This dog was participating in the third variation, with a time delay. © DogStudies. Belger & Bräuer, 2018. Metacognition in dogs: Do dogs know they could be wrong? Learning & Behavior. DOI: 10.3758/s13420-018-0367-5.

Some researchers argue that some animals, such as dogs, may only look for extra information when searching as a routinized, instinctual behavior, and not as a result of a metacognitive process. To control for this, Bräuer and Belger tested whether dogs show the so-called “passport effect,” originally described by researcher Joseph Call. When humans are looking for something very important, for example, a passport, they will engage in more active searching and will check for it more often than if they are looking for something less important or generic. Great apes display this same behavior – they will search more for a high-value food. Thus, Bräuer and Belger varied whether the dogs were looking for high- or low-value food, in order to test whether dogs also had the searching flexibility displayed in the passport effect. In another variation, they tested whether it made a difference to the dog when they had to search for a toy or for food.

The dogs “checked” more often when they did not know where the reward was hidden

The researchers found that the dogs did check significantly more often for the reward when they had not seen where it was placed. “These results show that dogs do tend to actively seek extra information when they have not seen where a reward is hidden,” explains Belger. “The fact that dogs checked more when they had no knowledge of the reward’s location could suggest that dogs show metacognitive abilities, as they meet one of the assumptions of knowing about knowing.”

Checking, however, did not always make the dogs very much more successful. In the first variation, with food or a toy as a reward, when dogs checked they were correct more often than when they did not check. However, in the second variation, with high-value or low-value food as the reward, even when dogs checked, they were not correct more than one would expect based on chance. The researchers theorize that this could be due to inhibition problems – the dogs get so excited about finding the reward, that they cannot stop themselves from approaching the closest fence even when they have seen that the reward is probably not there.

Additionally, the dogs did check more often for the toy than for the food in the first variation, suggesting that they do show flexibility in their searching and are not just engaging in a routine behavior. However, they did not check more often for the high-value food in the second variation, although they did look for it more quickly. Overall, the researchers concluded that the dogs, while showing some degree of searching flexibility, are not as flexible as primates.

In a third variation of the test, the dogs could always see where a food reward was placed, but were subject to a delay of 5 seconds to 2 minutes before being allowed to retrieve the reward. Interestingly, the dogs did not check more often with a longer time delay, even though they were slightly less successful. “It’s possible that this was due to a ‘ceiling effect,’ as dogs overall selected the correct fence in 93% of trials in this variation, so the pressure for seeking extra information was low,” suggests Belger.

Do dogs have metacognitive abilities?

The results did not allow the researchers to say definitively whether dogs possess metacognition, although they displayed some evidence for it. “For humans, vision is an important information gathering sense. In this case our experiment was based on a ‘checking’ action relying on sight – but the dogs probably also used their sense of smell when checking through the gap. We know that smell is very important for dogs and we could see that they were using it,” states Bräuer. “In future, we would like to develop an experiment investigating under what circumstances dogs decide to use their sense of smell versus sight. This may give us additional insights into their information seeking abilities.”

Source:   Max Planck Institute for the Science of Human History

No link between hypoallergenic dogs and lower risk of childhood asthma

Growing up with dogs is linked to a lower risk of asthma, especially if the dogs are female, a new study from Karolinska Institutet and Uppsala University in Sweden shows. However, the researchers found no relation between ‘allergy friendly’ breeds and a lower risk of asthma. The study is published in the journal Scientific Reports.

asthma and child

Children growing up with female dogs, but not with ‘allergy friendly’ dogs have a lower risk of asthma. Photo: iStock

Earlier studies have demonstrated a link between growing up with dogs and a lower risk of childhood asthma, but it has not been known whether this association is modified by dog characteristics. In this new study, the researchers have interrogated how variables such as sex, breed, number of dogs or size of dog are associated with the risk of asthma and allergy amongst children raised in a home with a dog during their first year of life.

“The sex of the dog can affect the amount of allergens released, and we know that uncastrated male dogs express more of a particular allergen than castrated dogs and female dogs,” says Tove Fall, Senior Lecturer at the Department of Medical Sciences – Molecular Epidemiology at Uppsala University, who led the study with Professor Catarina Almqvist Malmros at Karolinska Institutet. “Moreover, some breeds are described anecdotally as ‘hypoallergenic’ or ‘allergy friendly’ and are said to be more suitable for people with allergies, but there is no scientific evidence for this.”

Classified by different traits

The study included all children born in Sweden from 1 January 2001 to 31 December 2004 who had a dog in their home for the first year of life (23,600 individuals). Data from the Swedish population and health data registries were linked anonymously to two dog-owner registries from the Swedish Board of Agriculture and the Swedish Kennel Club. The dogs were classified by sex, breed, number, size and alleged ‘hypoallergenicity’.

The researchers then studied the relationship between the dogs’ characteristics and the risk of asthma and allergy diagnosis or the prescription of asthma or allergy drugs at the age of six. The statistical analyses controlled for all known confounders that could affect the risk of developing asthma or allergies, such as parental asthma/allergy, geographical location and number of siblings.

Their results showed that the prevalence of asthma at age six was 5.4 per cent. Children with only female dogs at home had a 16 per cent lower risk of asthma than those raised with male dogs. However, living with a male dog did not correlate with a higher risk than living with no dog at all. Children living with two or more dogs had a 21 per cent lower risk of asthma than those who only lived with one dog.

Hypoallergenic dogs linked to higher risk of allergy

Children of parents with asthma/allergies more often had breeds described as ‘hypoallergenic’ than children of parents without asthma/allergies – 11.7 per cent versus 7.6 per cent. Exposure to these breeds was associated with a 27 per cent higher risk of allergy but no increased risk of asthma.

“The likely explanation for this higher risk is that families with a history of allergy to furred pets more often choose these dogs, and also that ‘allergy friendly’ dogs do not in fact release less allergens,” says Catarina Almqvist Malmros, Professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet and Consultant at Astrid Lindgren Children’s Hospital.

“The finding should be treated with caution as we can say nothing about any actual causality,” she continues. “More studies are needed to monitor differences over time, measure the risk of allergies using biomarkers, and take account of the microflora.”

The study was financed with grants from the Swedish Research Council, the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM), Agria, Forte, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas), the Swedish Heart and Lung Foundation, Stockholm County Council (ALF funding) and the Strategic Research Programme in Epidemiology (SFO-epi) at Karolinska Institutet.

Source:  Karolinska Institutet media release

What Makes A Good Working Dog? Canine ‘Aptitude Test’ Might Offer Clues

The canine labor market is diverse and expansive. Assistance dogs may be trained to work with the visually or hearing impaired, or with people in wheelchairs. Detection dogs may be trained to sniff out explosives, narcotics or bedbugs. Other pups even learn to jump out of helicopters on daring rescue missions.

Despite the wide variety of working roles available for man’s best friend, those jobs can be tough to fill, since not every dog will qualify. Even among dogs specifically bred to be assistance dogs, for example, only about 50 percent that start a training program will successfully complete it, while the rest go on to be very well-trained family pets.

As a result, the wait list for a trained assistance dog can be up to two years.

Working Dogs

Shelby Smith was matched with her assistance dog Picasso through the nonprofit Canine Companions for Independence. UA researcher Evan MacLean is looking for ways to help organizations like Canine Companions identify promising assistance dogs sooner. (Photo: Bob Demers/UANews)

Evan MacLean, director of the Arizona Canine Cognition Center at the University of Arizona, is exploring ways to identify the best dogs for different jobs – before they start the long and expensive training process — by looking at their cognitive abilities.

He is lead author of a new study in Frontiers in Veterinary Science that looks at whether canines’ cognitive abilities can help predict their success as working dogs.

While a dog’s physical characteristics and temperament are often considered when thinking about which dog will be right for a given job, cognition is an area that’s received far less attention.

“People have really focused on temperament and how reactive a dog is to certain things in the environment,” said MacLean, assistant professor in the UA School of Anthropology. “What we were interested in was the fact that these dogs also face cognitive challenges. They have to learn all these things in the course of their training, and they have to be able to flexibly solve problems when things go wrong.”

MacLean’s study focuses on two types of working dogs: assistance dogs in training, which will go on to be paired with people with disabilities, and explosive detection dogs working for the U.S. Navy.

MacLean and his colleagues looked at the performance of both types of dogs on 25 different cognitive measures by using a battery of game-based tests, like hiding and finding objects and other forms of canine play.

What they found: A different set of skills predict whether a dog will be a good detection dog or a good assistance dog.

In the case of assistance dogs, social skills — including the ability to pay close attention to and maintain eye contact with humans — appear to be especially important. In detection dogs, good short-term memory and sensitivity to human body language, such as pointing gestures, were the best predictors of success.

“Dog jobs are just about as diverse as human jobs are,” MacLean said. “People sometimes think of working dogs as this general category of dogs that have jobs in society, but they actually have to do really, really different things, and because these jobs are so diverse, we didn’t expect that there was going to be one litmus test for what would make a good dog. It’s like if you think about aptitude testing with people – there are certain questions that will tell you something about one job but not another.”

The study involved 164 dogs from the California-based organization Canine Companions for Independence, which trains assistance dogs, and 222 dogs from the Navy.

The researchers tested the assistance dogs at 18 months old, when they first started a full-time, intensive six-month training program. Dogs in the study were considered “successful” based on whether or not they ultimately graduated from the training. Through cognitive testing, MacLean and his colleagues were able to predict the top 25 percent of graduates with 86 percent accuracy.

The success of the Navy dogs, whose training is ongoing and not marked by a single graduation date, was measured based on trainers’ records of the dogs’ performance on training exercises, as well as questionnaires with people who trained or deployed with the dogs.

MacLean’s findings suggest that cognition could be considered alongside temperament and physicality to predict working dog success.

If organizations that train dogs could better predict which dogs are most worth the investment, it could save tens of thousands of dollars in unnecessary training costs and also ensure that people in need get the right dogs faster, MacLean said.

He and his colleagues are now working on determining if cognitive testing could be informative even earlier — when a dog is just 8 weeks old. They also are looking at whether these skills have a genetic basis that could be targeted in breeding programs.

“One of the most exciting parts of all this is that it tells us cognition does something in animals,” MacLean said. “We study these abstract questions about how animals think about the world and how they solve problems, but there aren’t always a lot of situations where you can say, ‘Why does that matter? What does it allow an animal to actually do?’ This is some of the first evidence that suggests that these processes that we measure, which differ between individual dogs, have some real consequences related to something that’s quite worthy in society.”

Source:  University of Arizona media release

Yes, your pet can tell time

Are you taking your time when feeding your pet? Fluffy and Fido are on to you — and they can tell when you are dawdling.

time dog

A new study from Northwestern University has found some of the clearest evidence yet that animals can judge time. By examining the brain’s medial entorhinal cortex, the researchers discovered a previously unknown set of neurons that turn on like a clock when an animal is waiting.

“Does your dog know that it took you twice as long to get its food as it took yesterday? There wasn’t a good answer for that before,” said Daniel Dombeck, who led the study. “This is one of the most convincing experiments to show that animals really do have an explicit representation of time in their brains when they are challenged to measure a time interval.”

The research was published online this week in the journal Nature Neuroscience. Dombeck is an associate professor of neurobiology in Northwestern’s Weinberg College of Arts and Sciences.

When planning the study, Dombeck’s team focused on the medial entorhinal cortex, an area located in the brain’s temporal lobe that is associated with memory and navigation. Because that part of the brain encodes spatial information in episodic memories, Dombeck hypothesized that the area could also be responsible for encoding time.

“Every memory is a bit different,” said James Heys, a postdoctoral fellow in Dombeck’s laboratory. “But there are two central features to all episodic memories: space and time. They always happen in a particular environment and are always structured in time.”

To test their hypothesis, Dombeck and Heys set up an experiment called the virtual “door stop” task. In the experiment, a mouse runs on a physical treadmill in a virtual reality environment. The mouse learns to run down a hallway to a door that is located about halfway down the track. After six seconds, the door opens, allowing the mouse to continue down the hallway to receive its reward.

After running several training sessions, researchers made the door invisible in the virtual reality scene. In the new scenario, the mouse still knew where the now-invisible “door” was located based on the floor’s changing textures. And it still waited six seconds at the “door” before abruptly racing down the track to collect its reward.

“The important point here is that the mouse doesn’t know when the door is open or closed because it’s invisible,” said Heys, the paper’s first author. “The only way he can solve this task efficiently is by using his brain’s internal sense of time.”

By using virtual reality, Dombeck and his team can neatly control potentially influencing factors, such as the sound of the door opening. “We wouldn’t be able to make the door completely invisible in a real environment,” Dombeck said. “The animal could touch it, hear it, smell it or sense it in some way. They wouldn’t have to judge time; they would just sense when the door opened. In virtual reality, we can take away all sensory cues.”

But Dombeck and his team did more than watch the mice complete the door stop task over and over again. They took the experiment one step further by imaging the mice’s brain activity. Using two-photon microscopy, which allows advanced, high-resolution imaging of the brain, Dombeck and Heys watched the mice’s neurons fire.

“As the animals run along the track and get to the invisible door, we see the cells firing that control spatial encoding,” Dombeck said. “Then, when the animal stops at the door, we see those cells turned off and a new set of cells turn on. This was a big surprise and a new discovery.”

Dombeck noted these “timing cells” did not fire during active running — only during rest. “Not only are the cells active during rest,” he said, “but they actually encode how much time the animal has been resting.”

The implication of the work expands well beyond your impatient pooch. Now that researchers have found these new time-encoding neurons, they can study how neurodegenerative diseases might affect this set of cells.

“Patients with Alzheimer’s disease notably forget when things happened in time,” Heys said. “Perhaps this is because they are losing some of the basic functions of the entorhinal cortex, which is one of the first brain regions affected by the disease.”

“So this could lead to new early-detection tests for Alzheimer’s,” Dombeck added. “We could start asking people to judge how much time has elapsed or ask them to navigate a virtual reality environment — essentially having a human do a ‘door stop’ task.”

Source:   Northwestern University media statement

A dog’s colour could impact longevity, increase health problems

New research led by the University of Sydney has revealed the life expectancy of chocolate Labradors is significantly lower than their black and yellow counterparts.
Chocolate Labrador

The study of more than 33,000 United Kingdom-based Labrador retrievers of all colours shows chocolate Labradors also have a higher incidence of ear infections and skin disease. Its findings were published in the open access journal Canine Genetics and Epidemiology.

Part of the University’s VetCompass™ Programme, which collects and analyses electronic patient data on dogs, the research is being replicated in Australia, where Labradors are the most popular breed of dog.

In the UK, the median longevity of non-chocolate Labradors is 12.1 years, more than 10 percent longer than those with chocolate coats. The prevalence of ear inflammation (otitis externa) was twice as high in chocolate Labradors, who were four times more likely to have suffered from pyo-traumatic dermatitis (also known as hot-spot).

Lead author Professor Paul McGreevy, from the University’s Faculty of Science, said the relationship between coat colour and disease came as a surprise to researchers. The UK findings may not hold in Australian Labradors, he said, but warrant investigation.

“The relationships between coat colour and disease may reflect an inadvertent consequence of breeding certain pigmentations,” he said. “Because chocolate colour is recessive in dogs, the gene for this colour must be present in both parents for their puppies to be chocolate. Breeders targeting this colour may therefore be more likely to breed only Labradors carrying the chocolate coat gene. It may be that the resulting reduced gene pool includes a higher proportion of genes conducive to ear and skin conditions.”

Across the entire Labrador population, the most common health conditions found were obesity, ear infections and joint conditions.

“We found that 8.8 percent of UK Labradors are overweight or obese, one of the highest percentages among dog breeds in the VetCompass™ database,” Professor McGreevy said.

The prevalence was higher among male dogs who had been neutered.

Source:  University of Sydney media statement