Category Archives: research

Do Bigger Brains Equal Smarter Dogs?

Bigger dogs, with larger brains, perform better on certain measures of intelligence than their smaller canine counterparts, according to a new study led by the University of Arizona.

bigger vs smaller

Bigger dogs have better short-term memory and self-control than more petite pups. Credit: © alexzizu / Fotolia

Larger-brained dogs outperform smaller dogs on measures of executive functions – a set of cognitive processes that are necessary for controlling and coordinating other cognitive abilities and behaviors. In particular, bigger dogs have better short-term memory and self-control than more petite pups, according to the study published in the journal Animal Cognition.

“The jury is out on why, necessarily, brain size might relate to cognition,” said lead study author Daniel Horschler, a UA anthropology doctoral student and member of the UA’s Arizona Canine Cognition Center. “We think of it as probably a proxy for something else going on, whether it’s the number of neurons that matters or differences in connectivity between neurons. Nobody’s really sure yet, but we’re interested in figuring out what those deeper things are.”

Canine brain size does not seem to be associated with all types of intelligence, however. Horschler found that brain size didn’t predict a dog’s performance on tests of social intelligence, which was measured by testing each dog’s ability to follow human pointing gestures. It also wasn’t associated with a dog’s inferential and physical reasoning ability.

The study’s findings mirror what scientists have previously found to be true in primates – that brain size is associated with executive functioning, but not other types of intelligence.

“Previous studies have been composed mostly or entirely of primates, so we weren’t sure whether the result was an artifact of unique aspects of primate brain evolution,” Horschler said. “We think dogs are a really great test case for this because there’s huge variation in brain size, to a degree you don’t see in pretty much any other terrestrial mammals. You have chihuahuas versus Great Danes and everything in between.”

Horschler’s study is based on data from more than 7,000 purebred domestic dogs from 74 different breeds. Brain size was estimated based on breed standards.

The data came from the citizen science website Dognition.com, which offers instructions for dog owners to test their canines’ cognitive abilities through a variety of game-based activities. The users then submit their data to the site, where it can be accessed by researchers.

Short-term memory was tested by dog owners hiding a treat, in view of their dog, under one of two overturned plastic cups. Owners then waited 60, 90, 120 or 150 seconds before releasing their dog to get the treat. Smaller dogs had more difficulty remembering where the treat was hidden.

To test self-control, owners placed a treat in front of their seated dog and then forbade the dog from taking it. Owners then either watched the dog, covered their own eyes or turned away from the dog. Larger-breed dogs typically waited longer to snag the forbidden treat.

Horschler and his colleagues controlled for whether or not the dogs had been trained. They found that larger-brained breeds had better short-term memory and self-control than smaller dogs, regardless of the extent of training the dogs had received.

In the future, Horschler said he’d like to do comparative studies of cognitive abilities in different breed varieties, such as the miniature poodle and much larger standard poodle, which are essentially the same except for their size.

“I’m really interested in how cognition evolves and how that arises biologically,” Horschler said. “We’re coming to understand that brain size is in some way related to cognition, whether it’s because of brain size specifically or whether it’s a proxy for something else.”

Source:  University of Arizona media release

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Medical detection dogs help diabetes patients regulate insulin levels

New research by the University of Bristol in collaboration with Medical Detection Dogs has found that the best trained alert dogs have the potential to vastly improve the quality of life of people living with Type 1 diabetes.

As reported in PLOS One, on average trained dogs alerted their owners to 83 per cent of hypoglycaemic episodes in over 4,000 hypo- and hyper-glycaemic episodes that were examined. A hypoglycaemic episode is where blood sugar drops dangerously low and if left untreated, can lead to unconsciousness or even death.

medical alert assistance dog

Claire Pesterfield holding her dog Magic’s paw. He’s a medical alert assistant dog and has been trained to detect a minute shift in Claire’s blood sugar levels. She thinks he’s alerted and potentially saved her life 4,500 times in the five years they’ve been together. Photo by Trevor Martin

The findings confirm that alert dogs can help Type 1 patients regulate their blood sugars in a non-invasive way and avoid the risks of hypoglycaemic episodes and hyperglycaemia.

Lead author Dr Nicola Rooney from the Bristol Veterinary School, said: “We already know from previous studies that patients’ quality of life is vastly improved by having a medical detection dog. However, to date, evidence has come from small scale studies. Our study provides the first large-scale evaluation of using medical detection dogs to detect hypoglycaemia.”

In this study, researchers from Bristol, assessed the reliability of 27 trained glycaemia alert dogs, whose owners provided six to 12 weeks continual worth of blood records detailing every time the dog was alerted.

Medical Detection Dogs train pet dogs to respond to respond to the odour of human disease and help owners live with life-threatening diseases. Familiar with their owners, dogs are conditioned to respond with alerting behaviours when their owners’ blood sugar levels fall outside a target range.

Encouraged by the alerting behaviour of their pet dog, if such out-of-range (OOR) episodes occur, the patient can take appropriate action, usually by administering insulin or eating to retain the right glucose levels.

Dr Rooney, Teaching Fellow in Animal Welfare and Behaviour, added: “Our research shows a dog’s effectiveness is affected by the individual dog and its connection with its human partner. Since the usage of such dogs is growing, it’s important that any dogs used for these purposes are professionally trained, matched and monitored by professional organisations like Medical Detection Dogs.  It’s also vital that research continues both to assess true efficacy and determine ways to optimise their performance.”

Dr Claire Guest, Chief Executive and co-founder of Medical Detection Dogs, said: “The findings are fantastic news for all those who are living with Type 1 diabetes and other conditions. Medical detection dogs primarily serve patients looking for more effective and independent ways of managing their condition.

“Our dogs also serve the wider medical community by offering proactive solutions that are natural, non-invasive and have been shown to provide countless psychological benefits.

“As our natural companions, and with a highly refined sense of smell, why shouldn’t they be able to detect changes in our personal health?”

Paper:

How effective are trained dogs at alerting their owners to changes in blood glycaemic levels?: variations in performance of  glycaemia alert dogs by Nicola J Rooney, Claire M Guest, Lydia CM. Swanson, Steve V. Morant in PLOS One [open access]

Source:  University of Bristol media release

Bulldogs’ Screw Tails Linked to Human Genetic Disease

With their small size, stubby faces and wide-set eyes, bulldogs, French bulldogs and Boston terriers are among the most popular of domestic dog breeds. Now researchers at the University of California, Davis, School of Veterinary Medicine have found the genetic basis for these dogs’ appearance, and linked it to a rare inherited syndrome in humans.

bulldog

Moxie, a 3-year-old French bulldog, took part in a study of the genetics of “screwtail” dog breeds (bulldogs, French bulldogs and Boston terriers). A common mutation in these dogs is similar to genetic changes in a rare human disease, Robinow syndrome. (Photo credit: Katy Robertson)

Bulldogs, French bulldogs and Boston terriers aren’t the only dogs with short, wide heads, but they do share another feature not found in other breeds: a short, kinked tail or “screwtail,” said Professor Danika Bannasch, Department of Population Health and Reproduction in the UC Davis School of Veterinary Medicine. These three breeds all lack the vertebrae that make up the tail bone, she said.

The researchers sequenced the whole genome — the entire DNA sequence — of 100 dogs, including 10 from screwtail breeds. All the participating dogs were privately owned pets seen at the UC Davis Veterinary Medical Teaching Hospital, whose owners agreed to participate. Graduate students Tamer Mansour and Katherine Lucot, with C. Titus Brown, associate professor at the School of Veterinary Medicine and Genome Center, searched through the DNA sequences to find changes associated with screwtail breeds.

From more than 12 million individual differences they were able to identify one mutation, in a gene called DISHEVELLED 2 or DVL2. This variant was found in 100 percent of the bulldogs and French bulldogs sampled, and was very common in Boston terriers.

This kind of whole genome comparison is relatively new, Bannasch said.

“Normally, we would have first had to identify a region DNA and work from there,” she said. “We could look at breed-specific traits, but not as well as we can now.”

Professor Henry Ho at the UC Davis School of Medicine studies similar genes in humans. Mutations in the related DVL1 and DVL3 genes are known to cause Robinow syndrome, a rare inherited disorder in humans characterized by strikingly similar anatomical changes — a short, wide “babyface,” short limbs and spinal deformities. In addition, Robinow patients and the screwtail breeds also share other disease traits, such as cleft palate. In both humans and dogs, DVL genes are part of a signaling pathway called WNT involved in development of the skeleton and nervous system, among other things, said Peter Dickinson, professor of surgical and radiological sciences at the School of Veterinary Medicine. By characterizing the screwtail DVL2 protein product, Sara Konopelski, a graduate student in the Ho lab, pinpointed a key biochemical step in the WNT pathway that is disrupted by the mutation. This finding further suggests that a common molecular defect is responsible for the distinct appearances of both Robinow patients and screwtail dog breeds.

The DVL2 screwtail mutation is so common in these breeds, and so closely tied to the breed appearance, that it would be difficult to remove it by breeding, Dickinson said. Other genes are known to contribute to short, wide “brachycephalic” heads in dogs, and there are likely multiple genes that contribute both to appearance and to chronic health problems in these breeds.

Understanding a common mutation in popular dog breeds may, however, give more insight into the rare Robinow syndrome in humans. Only a few hundred cases have been documented since the syndrome was identified in 1969.

“It’s a very rare human disease but very common in dogs, so that could be a model for the human syndrome,” Bannasch said.

Source:  UC Davis media release

Research reveals overweight dogs may live shorter lives

New research from the University of Liverpool and Mars Petcare’s WALTHAM Centre for Pet Nutrition reveals overweight dogs are more likely to have shorter lives than those at ideal body weights.

Results from the study, conducted retrospectively across two decades and published in the Journal of Veterinary Internal Medicine, revealed the lifespan of dogs that were overweight was up to two and a half years shorter when compared to ideal-weight dogs.

fat bulldog

The study examined more than 50,000 dogs across 12 of the most popular dog breeds. The effect of being overweight was seen in all breeds, although the magnitude of the effect differed, ranging from between five months less for male German Shepherds to two years and six months less for male Yorkshire Terriers.

Poorer quality of life

It is estimated that over a quarter of households (26%) in the UK and nearly half in the US (47.6%) own a dog. However despite our affection for canine companions, concern is growing that many pet owners are unaware of the serious health implications of dogs carrying extra weight. Pet obesity is steadily on the rise, with latest figures estimating one in three dogs and cats in the U.S. is overweight.

Although the study did not examine the reasons behind the extra pounds in dogs, feeding habits are thought to play a role in pet obesity. According to a recent Better Cities For Pets survey , more than half (54%) of cat and dog owners always or often give their pet food if they beg for it, and nearly a quarter (22%) of cat and dog owners sometimes overfeed their pet to keep them happy.

Study co-author and Professor of Small Animal Medicine at the University of Liverpool Alex German, said: “Owners are often unaware that their dog is overweight, and many may not realise the impact that it can have on health. What they may not know is that, if their beloved pet is too heavy, they are more likely to suffer from other problems such as joint disease, breathing issues, and certain types of cancer, as well as having a poorer quality of life. These health and wellbeing issues can significantly impact how long they live.

“For many owners, giving food, particularly tasty table scraps and tidbits, is the way we show affection for our pets. Being careful about what you feed your dog could go a long way to keeping them in good shape and enabling them to be around for many years to come.
“Worryingly, it is estimated only one in five pet owners always measures how much food they are giving their pet, with four in five (87%) always or often simply estimating the amount of food they think their pet needs at each serving.”

About the Study

The University of Liverpool and WALTHAM study was a retrospective, observational cohort study that leveraged demographic, geographic and clinical data from dogs that received care at BANFIELD® Pet Hospitals between April 1994 and September 2015. Data were available from 50,787 dogs across 12 of the most popular family breeds: Dachshund, German Shepherd, Golden Retriever, Labrador Retriever, American Cocker Spaniel, Beagle, Boxer, Chihuahua, Pit Bull Terrier, Pomeranian, Shih Tzu, and Yorkshire Terrier. For each breed, the lifespan dogs whose owners reported them to be overweight and those in optimal body condition was compared.

As the largest general-veterinary practice in the world, Banfield has more than 1,000 hospitals across the United States and Puerto Rico comprised of veterinary teams who are committed to providing high-quality veterinary care for more than three million pets annually. The data extracted for this study included demographic (breed, sex, neuter status and date of birth) and geographic (latitude and longitude of the owner’s postcode) variables, plus data collected during in-clinic visits (date of visit, bodyweight and if available body condition), and date of death. Pedigree status and date of birth are both owner-reported parameters and were not verified by veterinary staff.

Source:  University of Liverpool

For gait transitions, stability often trumps energy savings

A dog’s gait, according to the American Kennel Club, is “the pattern of footsteps at various rates of speed, each distinguished by a particular rhythm and footfall.” When dogs trot, for example, the right front leg and the left hind leg move together. This is an intermediate gait, faster than walking but slower than running.

In the December 12, 2018 issue of the Proceedings of the Royal Society B, a multi-institutional team of researchers based at the University of Chicago Medical Center take a novel and wide-ranging approach to understanding such speed-related gait transitions. The generally accepted approach has long focused on reducing locomotor costs, essentially finding the least taxing way to ramp up from one gait to a faster one without wasting energy.

gait transitions

Each animal ran in the metabolic chamber two to five times a day. From these metrics it was possible to determine the energetic costs of running at a particular speed. Credit: Caleb Bryce from the Botswana Predator Conservation Trust

The researchers, however, uncovered a different explanation. They chose to focus less on energy conservation and more on locomotor instability–in layman’s terms, reducing the risk of stumbling or toppling over. Their findings suggest that gait transitions represent “predictive, anticipatory switching of movements to minimize unstable dynamic states.”

“We found that gait transitions occur when the stability of a gait decreases so much that switching to a new gait improves stability,” said Michael Granatosky, PhD, lead author of the study and a post-doctoral student in the department of Organismal Biology and Anatomy at the University of Chicago. “The mammals and birds we studied tend to make gait transitions at critical points to provide a more rhythmic, less unstable locomotor state.”

These transitions, he added, can minimize “high inter-stride variation and unstable dynamic states, reducing the risk of inter-limb interference, such as tripping or falling.”

This wide-ranging study focused on gait transitions in nine animal models–seven mammals and two birds. The researchers started with Virginia opossums, tufted capuchins (“organ grinder” monkeys) and domestic dogs.

They subsequently found similar data on gait transitions in six additional species: American minks, Australian water rats, brush-tailed bettongs (small marsupials also known as rat kangaroos), ostriches, North American river otters and the Svalbard rock ptarmigan.

All of the initial animals–dogs, monkeys and opossums–were trained to exercise at a range of speeds on a treadmill within a plexiglass metabolic chamber. This familiarized the animals with the treadmills while improving their physical fitness. By the end of the training period, all of the animals could sustain six to ten minutes of vigorous running at “speeds required for metabolic movements.”

Once the training was completed, the researchers began testing. They monitored oxygen uptake, carbon-dioxide production, temperature, moisture levels, barometric pressure and air flow. Each animal ran in the chamber two to five times a day. From these metrics it was possible to determine the energetic costs of running at a particular speed.

These energetic costs were collected over a range of speeds during walking and running. Variations in stride cycle duration were collected for each speed interval.

Based on the data collected from this broad phylogenetic range of species, the authors determined that the assumptions of the energetic minimization hypothesis for gait transitions were rarely met.

Instead, most animals choose not to switch gaits when it was most energetically efficient. In this study, dogs, ptarmigans, ostriches and otters, showed no significant change in the energy cost of transport while switching from a walk to a faster mode. In contrast, almost all of the other species demonstrated high variability near gait transitions. They subsequently reduced variability after switching to a new more stable gait.

“Energy savings do not predict gait transition patterns,” the authors conclude. Instead, gait transitions “maintain dynamic stability across a range of speeds.”

“Our data,” the authors conclude, “suggest that gait transitions represent predictive, anticipatory switching of movement types to minimize high variability and avoid unstable dynamic states.” Birds and mammals, they added, appear to have evolved sensorimotor mechanisms for monitoring inter-stride stability during locomotion and for triggering gait transitions at critical levels of variation.

Source:  EurekAlert!

Training children and adults in dog body language

A better understanding of the way dogs communicate distress could be the first step in reducing the risk of dog bites for both children and adults, a new study has found.

Psychologists investigating how children and parents perceive and interpret dog’s body language found that both groups significantly underestimate and misinterpret the way that dogs display distress or anxiety, including behaviours such as snarling or growling which can cause a significant risk to children.

Lip licking dog
The project consisted of three phases involving children aged three, four and five years old and one group of parents. Initially, each group was shown a series of short video clips of dogs displaying a full range of behavioural signals which ranged from happy dogs through to high-risk conflict-escalating behaviours such as growling, snarling or biting. Participants were then asked to rate their perception of the behaviours on a simple, child-friendly scale from ‘very happy’ to ‘very unhappy/very angry’.

The groups then took part in a training phase where the videos were repeated, this time accompanied by simple information explaining the type of behaviour the dog was displaying, for example, ‘the dog is licking its nose’, how to interpret the behaviour – i.e. the dog is worried, followed by a safety message such as ‘you should leave the dog alone’. Participants then also saw novel videos with all behaviours. Once the training phase was completed, participants were immediately tested to establish their judgements of the dogs’ behaviours then testing again after six months and after one year to measure whether the training had a lasting effect.

Results showed that younger children found it harder to correctly interpret dog distress signals with 53 per cent of three year olds misinterpreting high risk signals such as growling or snarling. Of the children who made mistakes, 65 per cent thought that these dogs were happy. Results showed 17per cent of the parents also incorrectly interpreted these behaviours.

After the training intervention, both children and adults showed better understanding. Most improvement was found on conflict-escalating signals such as staring, growling or snarling with adults and older children showing the highest levels of improvement. Pre-training, only 55 per cent of four year olds were able to correctly interpret high risk dog behaviours with this rising to 72 per cent post training. The training was also shown to have a lasting effect with the figure rising to 76 per cent twelve months post-training.

Lead researcher Professor Kerstin Meints from the University of Lincoln’s School of Psychology said: “We observed that children often try to apply an explanation for the dog’s signals that would be appropriate to explain human behaviour. For example, children often wrongly interpreted a dog snarling and showing its teeth to mean that the dog was happy, which could put them at significant risk if they were to approach a dog displaying these signals.

“This project is the first to offer an intervention to significantly enhance children’s and adults’ abilities to correctly interpret dog signalling and has shown that with simple training we can improve their awareness, knowledge, recognition and interpretation skills.”

Journal citation:  Teaching Children and Parents to Understand Dog Signalling, Frontiers in Veterinary Science, https://www.frontiersin.org/articles/10.3389/fvets.2018.00257/full

Source:  University of Lincoln media release

Women sleep better with dogs than with human partners

There are many dog trainers who advise against letting your dog sleep with you in bed.  Some new research by Dr Christy Hoffman at the Canisius College will challenge that notion.

Izzy the greyhound in bed

In a survey of 962 women living in the United States, dogs who slept with their female owners were found to disturb sleep less than a human counterpart and they provided stronger feelings of comfort and security.

Dogs’ sleep patterns more closely coincide with sleep patterns in humans than do the sleep patterns of cats, which may explain why dog moms stick to a stricter sleep schedule and go to bed earlier.

Cats didn’t fare quite as well in this research.  Cats were reported to be equally disruptive as human partners and were associated with weaker feelings of comfort and security compared to dogs or humans.

Journal citation:  An Examination of Adult Women’s Sleep Quality and Sleep Routines in Relation to Pet Ownership and Bedsharing

Source:  Canisius College