Category Archives: research

UCLA researcher finds that feeding pets creates the equivalent of 64 million tons of carbon dioxide a year

Note from DoggyMom:  It’s important for us to understand the environmental impacts of our activities.

On a scale with the huge consumption of meat in the USA, not to mention the environmental impacts of livestock production in other countries such as New Zealand’s dairy industry, the impact of pets is minor in comparison.

I recommend home-cooking and particularly the use of toppers with commercial foods to use meat leftovers and organ meats that we often discard.  But more importantly, if you move your human family to a plant-based diet, this will hugely offset any impacts from your pets eating meat!


With many Americans choosing to eat less meat in recent years, often to help reduce the environmental effect of meat production, UCLA geography professor Gregory Okin began to wonder how much feeding pets contributes to issues like climate change.

All that meat has important consequences. Okin calculated that meat-eating by dogs and cats creates the equivalent of about 64 million tons of carbon dioxide a year, which has about the same climate impact as a year’s worth of driving from 13.6 million cars.

dog eating food out of a bowl

Photo by: Patricia Marroquin/UCLA

“I like dogs and cats, and I’m definitely not recommending that people get rid of their pets or put them on a vegetarian diet, which would be unhealthy,” Okin said. “But I do think we should consider all the impacts that pets have so we can have an honest conversation about them. Pets have many benefits, but also a huge environmental impact.”

In a paper published  in the journal PLOS One, Okin says he found that cats and dogs are responsible for 25 to 30 percent of the environmental impact of meat consumption in the United States. If Americans’ 163 million Fidos and Felixes comprised a separate country, their fluffy nation would rank fifth in global meat consumption, Okin calculated, behind only Russia, Brazil, the United States and China. And it all has to go somewhere — America’s pets produce about 5.1 million tons of feces in a year, as much as 90 million Americans. If all that were thrown in the trash, it would rival the total trash production of Massachusetts — from the humans, at least.

Compared to a plant-based diet, meat requires more energy, land and water to produce, and has greater environmental consequences in terms of erosion, pesticides and waste, Okin noted. Previous studies have found that the American diet produces the equivalent of 260 million tons of carbon dioxide from livestock production. By calculating and comparing how much meat 163 million cats and dogs eat compared to 321 million Americans, Okin determined how many tons of greenhouse gases are tied to pet food.

His calculations start with publicly available information, like the number of dogs and cats in the country and the ingredients in market-leading pet foods, leading to complicated equations like the mathematical menagerie below, and producing estimates that create a starting point for conversation.

He found that the nation’s dogs and cats eat about 19 percent as many calories as the nation’s people, on par with all the calories consumed by the population of France in a year. Because dog and cat food tends to have more meat than the average human diet, this means that dogs and cats consume about 25 percent of the total calories derived from animals in the United States.

Okin, a member of UCLA’s Institute of the Environment and Sustainability, usually researches dust bowls, desert landscape dynamics and wind erosion, and how those things can impact individual ecosystems and the global climate. Pinning down the environmental impact of canine companions and feline friends was more of an — ahem — pet project that occurred to him while he was thinking about the growing trend of raising backyard chickens.

“I was thinking about how cool it is that chickens are vegetarian and make protein for us to eat, whereas many other pets eat a lot of protein from meat,” he said. “And that got me thinking — how much meat do our pets eat?”

Okin recognizes that some of the products in pet food aren’t something people should or would eat. But some of it is. In his research, he confirmed his hunch that premium pet foods usually contain more animal products than other brands, and that premium pet food purchases are increasing. As growing numbers of people consider pets less as animals and more as family members, Okin said, pampering has increased and the options for pet food with high-quality meat has kept pace. This means pets are increasingly eating cuts of meat suitable for humans.

“A dog doesn’t need to eat steak,” Okin said. “A dog can eat things a human sincerely can’t. So what if we could turn some of that pet food into people chow?”

A commitment to snout-to-tail consumption, where as much rendered product as possible is produced for human use, could significantly reduce national meat consumption. Okin estimates that if even a quarter of the meat in pet food could be consumed by humans, it would equal the amount of meat consumed by 26 million Americans, nearly the population of Texas. Okin noted that ideas about what is edible vary dramatically by culture. He also pointed to a controversy in 2012 about “pink slime,” also called lean finely textured beef.

“It’s perfectly edible and completely safe, but it’s unappetizing, so people don’t want it in their food,” Okin said. “But frankly, it’s a good, inexpensive protein source.”

As eating less meat expands from vegetarian to environmental circles as a way to reduce one’s carbon footprint, considering what to feed pets is a natural next step, Okin said. It’s not just an issue in the United States, he noted. In places like China, Brazil and other emerging countries, as the population becomes more affluent, they’re eating more meat and they’re getting more pets.

“I’m not a vegetarian, but eating meat does come at a cost,” he continued. “Those of us in favor of eating or serving meat need to be able to have an informed conversation about our choices, and that includes the choices we make for our pets.”

He doesn’t see a simple solution. Pets provide friendship and other social, health and emotional benefits that can’t be discounted, Okin said. People concerned about meat intake could consider vegetarian pets, like birds or hamsters, he suggested. The pet food industry, he noted, is also beginning to take steps toward sustainability, and could work to reduce overfeeding and consider alternative sources of protein. But it’s a complicated issue, and where pets are concerned, Okin knows it’s important to have a sense of humor about it.

“Maybe we could all have little ponies,” he said, half-jokingly. “We’d all get more exercise taking them for walks, and they would also mow the lawn.”

Source:  UCLA Newsroom

Elevated cholesterol’s link with canine osteosarcoma includes a better prognosis

Note from Doggy Mom:  I follow lots of areas of research in the canine field, but anything to do with osteosarcoma is interesting to me since greyhounds are known for suffering from this type of cancer.  Izzy is a greyhound!


Usually thought of as a health detriment, elevated cholesterol may play a role in longer survival times for dogs with a common form of bone cancer.

In addition to their veterinary significance, the findings by Oregon State University researchers advance the understanding of a type of malignant tumor, osteosarcoma, that’s often diagnosed in humans as well, typically afflicting teenagers and young adults.

Dog with cancer

A dog with osteosarcoma; Photo courtesy of Oregon State University

“This is one of the first steps into identifying cholesterol as a potential biomarker for canine osteosarcoma,” said Haley Leeper, a veterinary oncology resident at the OSU College of Veterinary Medicine. “We don’t have answers as to why high cholesterol is associated with this disease and with a better prognosis, but we’re hoping to advance these findings in future research.”

Leeper and collaborators at OSU and Iowa State University compared 64 dogs with osteosarcoma against two control groups: 30 dogs that had suffered traumatic bone fractures and 31 healthy dogs similar in age and weight to the animals with cancer.

Researchers found nearly half of the dogs with cancer – 29 of the 64 – had elevated levels of total serum cholesterol, a dramatically higher rate than occurred in either control population; just three of the 30 dogs with broken bones, and only two of the 31 healthy animals, showed high cholesterol.

Of the dogs stricken with osteosarcoma, 35 had the cancer in a leg which was subsequently amputated, followed by chemotherapy, which is the standard-of-care treatment; the dogs with elevated total cholesterol had a median survival time of 455 days, more than 200 days greater than the median survival time  for dogs with normal cholesterol.

“When people think of cholesterol they think of cheeseburgers and heart attacks,” Leeper said. “However, cholesterol is involved with many key processes and structures in the body like cell membranes, bone health and the immune system.”

Future studies that follow dogs long term and look at specific lipid content in the blood may shed light on the mechanisms behind cholesterol’s role in enhanced survival, Leeper said.

“There are a lot of things we plan on investigating,” she said. “This is exciting and fascinating, partly due to the comparative medical aspects between human research and our research.”

Source:  Oregon State University media release

Dog walking could be key to ensuring activity in later life

A new study has shown that regularly walking a dog boosts levels of physical activity in older people, especially during the winter.

Published in the Journal of Epidemiology and Community Health, the study used data from the EPIC Norfolk cohort study, which is tracking the health and wellbeing of thousands of residents of the English county of Norfolk.

The researchers from the University of East Anglia (UEA) and Centre for Diet and Activity Research (CEDAR) at the University of Cambridge found that owning or walking a dog was one of the most effective ways to beat the usual decline in later-life activity, even combatting the effects of bad weather.

Dog owners were sedentary for 30 minutes less per day, on average.

More than 3000 older-adults participating in the study were asked if they owned a dog and if they walked one. They also wore an accelerometer, a small electronic device that constantly measured their physical activity level over a seven-day period.

As bad weather and short days are known to be one of the biggest barriers to staying active outdoors, the researchers linked this data to the weather conditions experienced and sunrise and sunset times on each day of the study.

Lead author of the paper, Dr Yu-Tzu Wu, said “We know that physical activity levels decline as we age, but we’re less sure about the most effective things we can do to help people maintain their activity as they get older.

“We found that dog walkers were much more physically active and spent less time sitting overall. We expected this, but when we looked at how the amount of physical activity participants undertook each day varied by weather conditions, we were really surprised at the size of the differences between those who walked dogs and the rest of the study participants.”

The team found that on shorter days and those that were colder and wetter, all participants tended to be less physically active and spent more time sitting. Yet dog walkers were much less impacted by these poor conditions.

Project lead Prof Andy Jones, from UEA’s Norwich Medical School, said: “We were amazed to find that dog walkers were on average more physically active and spent less time sitting on the coldest, wettest, and darkest days than non-dog owners were on long, sunny, and warm summer days. The size of the difference we observed between these groups was much larger than we typically find for interventions such as group physical activity sessions that are often used to help people remain active.”

The researchers caution against recommending everyone owns a dog, as not everyone is able to look after a pet, but they suggest these findings point to new directions for programmes to support activity.

Prof Jones said: “Physical activity interventions typically try and support people to be active by focussing on the benefits to themselves, but dog walking is also driven by the needs of the animal. Being driven by something other than our own needs might be a really potent motivator and we need to find ways of tapping into it when designing exercise interventions in the future.”

Source:  University of East Anglia press release

 

Search and rescue dogs do their job despite travel stress

When disaster strikes, you want the very best tools, functioning at their peak. In the case of catastrophic earthquakes, tornadoes, or even bombings in war zones, those tools are search and rescue dogs. But researchers have found that getting dogs to disaster sites can add to the animals’ stress.

“We’ve spent $16 billion in this country trying to come up with a machine that can sniff better than dogs, and we haven’t done it yet. Search and rescue animals can save lives, protect our soldiers in the field, and locate survivors after a disaster. We want to know how we can manage them so we can protect their performance, because their performance impacts human lives. That’s the reason behind what we do,” says Erin Perry, an assistant professor in the Department of Animal Science, Food and Nutrition at Southern Illinois University.

Perry, who has also been a canine handler in the Department of Homeland Security for the past 14 years, teamed up with University of Illinois animal scientist Kelly Swanson and others at U of I to learn how stress affects the animals’ performance on the job.

Search and rescue dogs fly on a moment’s notice to the site of a disaster, where they are expected to perform at the top of their game. But, just like for humans, flying can be stressful for dogs. The research team designed two preliminary studies to evaluate the effect of air travel stress on the animals’ physiology and job performance.

“Some dogs are like, ‘I’ve flown before, no big deal,’ but others, even if they’ve flown before, still show stress behaviors, and can have elevated body temperature or diarrhea,” says Swanson, Kraft Foods Human Nutrition Endowed Professor in the Department of Animal Sciences and the Division of Nutritional Sciences at U of I.

Dog owners may be familiar with the tendency towards loose stools when their animals are stressed. One of the reasons for that may be a stress-induced change in gut physiology and shift in the gut microbiome, the community of microbes that inhabit the mammalian gut. Paired with a more permeable [or leaky] gut lining, also triggered by stress, “bad” microbes can gain an advantage and cause upset stomachs. These symptoms have been observed in search and rescue dogs when traveling to a work site, but no one had ever studied the dogs’ microbiome.

In one of the studies by Perry and Swanson’s team, search and rescue dogs were flown for 2.5 hours in the cabin of a commercial airliner to the job site. In the other, dogs were “hot loaded” into a helicopter – blades whirling – for a quick 30-minute flight to the site. The team looked at slightly different factors in each study, but for both, they examined changes in the makeup of the microbiome and performance on the job.

Helicopter Study dogs approaching_1

Dogs being loaded into a helicopter

The helicopter flight caused spikes in body temperature and the stress hormone cortisol, but the researchers didn’t observe changes in the makeup of the dogs’ microbiomes. Dogs that entered an airport, went through security, and flew for a longer period on the commercial flight showed an interesting microbial shift.

“Microbial beta diversity, which is a measure of the presence and abundance of bacterial taxa, was different between dogs that traveled compared to those that did not. Travel led to greater relative abundances of Clostridia and Bacteroidaceae populations, two of the more predominant microbial groups in the gastrointestinal tract,” Swanson explains. He says more research is needed to understand how such changes may impact the long-term health of search and rescue dogs.

But the most impressive finding in both studies was the fact that there was no effect of air travel stress on the dogs’ job performance. “They showed behavioral stress, their gut was completely turned upside down, their bloodwork showed significant effects, and it didn’t matter. They still went to work and performed beautifully,” Perry says. “Even though we see physiological impacts on these dogs, they’re such amazing athletes that they overcome the physical and environmental stress and just do their job.”

Although travel didn’t impact the dogs’ performance in these preliminary studies, the researchers emphasized that stress can occasionally cause search and rescue dogs to miss work. But gaining new insight into canine stress responses, particularly the way stress affects the microbiome, may pave the way towards potential solutions for both working and companion animals.

“We’ve all owned dogs that were scared of lightning, vacuum cleaners, those innocuous day-to-day experiences,” Perry says. “Having a better understanding of what causes stress and how to compensate for it helps every dog, not just the ones that are out there saving lives.”

Swanson adds, “These small studies are just a starting point. In the future, we hope to apply these findings to larger studies focused on various stressor types and a longer duration of stress, similar to that experienced in the field during times of emergency. Our goals will be to develop and evaluate nutritional interventions and/or management strategies that avoid negative physiologic effects and maintain performance.”

Source:  University of Illinois media release

Researchers identify a common underlying genetic basis for social behavior in dogs and humans

Dogs’ ability to communicate and interact with humans is one the most astonishing differences between them and their wild cousins, wolves. A new study published in the journal Science Advances identifies genetic changes that are linked to dogs’ human-directed social behaviors and suggests there is a common underlying genetic basis for hyper-social behavior in both dogs and humans.

An interdisciplinary team of researchers, including those from Princeton University, sequenced a region of chromosome 6 in dogs and found multiple sections of canine DNA that were associated with differences in social behavior. In many cases, unique genetic insertions called transposons on the Williams-Beuren syndrome critical region (WBSCR) were strongly associated with the tendency to seek out humans for physical contact, assistance and information.

In contrast, in humans, it is the deletion of genes from the counterpart of this region on the human genome, rather than insertions, that causes Williams-Beuren syndrome, a congenital disorder characterized by hyper-social traits such as exceptional gregariousness.

“It was the remarkable similarity between the behavioral presentation of Williams-Beuren syndrome and the friendliness of domesticated dogs that suggested to us that there may be similarities in the genetic architecture of the two phenotypes,” said Bridgett vonHoldt, an assistant professor in ecology and evolutionary biology at Princeton and the study’s lead co-author.

Dogs ability to communicate

Dogs’ ability to communicate and interact with humans is one of the most astonishing differences between them and their wild cousins, wolves. Shown here, Lauren Brubaker, a graduate research assistant in the Department of Animal and Rangeland Sciences at Oregon State University and one of the study’s authors, interacts with a gray wolf. Photo by Monty Sloan

VonHoldt had identified the canine analog of the WBSCR in her publication in Nature in 2010. But it was Emily Shuldiner, a 2016 Princeton alumna and the study’s other lead co-author, who, as part of her senior thesis, pinpointed the commonalities in the genetic architecture of Williams-Beuren syndrome and canine tameness.

By analyzing behavioral and genetic data from dogs and gray wolves, vonHoldt, Shuldiner and their colleagues reported a strong genetic aspect to human-directed social behavior by dogs. Monique Udell, an assistant professor of animal and rangeland sciences at Oregon State University and the paper’s senior author, collected and analyzed the behavioral data for 18 domesticated dogs and 10 captive human-socialized wolves, as well as the biological samples used to sequence their genomes.

First, Udell quantified human-directed sociability traits in canines, such as to what extent they turned to a human in the room to seek assistance in trying to lift a puzzle box lid in order to get a sausage treat below or the degree to which they sought out social interactions with familiar and unfamiliar humans. Then, vonHoldt and Shuldiner sequenced the genome in vonHoldt’s lab and correlated their findings.

Consistent with their hypothesis, the researchers confirmed that the domesticated dogs displayed more human-directed behavior and spent more time in proximity to humans than the wolves. The also discovered that some of these transposons on the WBSCR were only found in domestic dogs, and not in wolves at all.

VonHoldt’s findings suggest that only a few transposons on this region likely govern a complex set of social behaviors. “We haven’t found a ‘social gene,’ but rather an important [genetic] component that shapes animal personality and assisted the process of domesticating a wild wolf into a tame dog,” she said.

Anna Kukekova, an assistant professor in the Department of Animal Sciences at the University of Illinois at Urbana-Champaign who is familiar with the research but had no role in it, said that the paper points to these genes as being evolutionarily conserved, or essentially unchanged throughout evolution. “The research provides evidence that there exist certain evolutionary conservative mechanisms that contribute to sociability across species,” she said. “That they have found that this region contributes to sociability in dogs is exciting.”

The researchers’ evidence also calls into question the role of domestication in the evolution of canine behavior. Most experts agree that the first domesticated dogs were wolves that ventured into early human settlements. These proto-dogs evolved not only in their looks, but also their behavior, a process likely influenced by the species’ cohabitation, according to vonHoldt.

However, unlike previous research which suggests that, during the process of domestication, dogs were selected for a set of cognitive abilities, particularly an ability to discern gesture and voice, vonHoldt and Shuldiner’s research posits that dogs were instead selected for their tendency to seek human companionship.

“If early humans came into contact with a wolf that had a personality of being interested in them, and only lived with and bred those ‘primitive dogs,’ they would have exaggerated the trait of being social,” vonHoldt said.

Source:  Princeton University media statement

Dogs help in breast cancer research

Cancer is one of the most frequent diseases not only in people, but in pets as well. Like people, dogs can also suffer from cancer of the mammary glands (mammary tumors). Dog mammary tumors are very similar to breast carcinoma in humans, and much more so than those of rats or mice, for example. For this reason, research on canine mammary tumors is important for human medicine as well. A study performed at the University of Zurich has now shown how similar mammary tumors are in both people and dogs.

Enni Markkanen, Vetsuisse-Fakultät Zürich, Untersuch Hund

Cancerous cells reprogram healthy cells

For the development of tumors and the progression of a carcinoma, not only the characteristics of the cancer cells themselves are decisive, but also the cells surrounding the tumor play a major role in this. Many tumors even have the capability to reprogram healthy cells in the tumor environment in a way that they start to support the growth of the cancerous cells. This mechanism plays an essential role in human breast carcinoma – but is it the same for dogs? The similarity of breast carcinoma in dogs and humans has been known for a long time. “But whether these tumor cells also influence the surrounding tissue in dogs the same way they do in humans was unknown until now”, explains Enni Markkanen of the Institute of Pharmacology and Toxicology of the Vetsuisse Faculty of the University of Zurich.

Archived tissues are of great value to the research

The researchers analyzed the surrounding tissue of canine mammary tumors using molecular biology and immunohistological methods. To do this, they could access the tissue archive of the Institute of Veterinary Pathology located at the Animal Hospital. “With the permission of our patient’s owners, we conduct pathological tests to better understand diseases,” says animal pathologist Alexandra Malbon. “In the process, we archive samples of various organs and tissues as these samples can be of great value to answer future research questions.”

Dogs suffering from cancer aid cancer research for humans

In the archived samples of mammary tumors from dog patients, Enni Markkanen and her team were able to prove that some cells in the vicinity of tumors behave the same way as the corresponding cells in humans: In the healthy tissue surrounding the tumor, substances are produced that promote tumor growth. “Simply speaking, the tumor enslaves its environment: It forces the surrounding cells to work for its benefit,” Markkanen adds. This mechanism works the same in both humans and dogs. For research on breast carcinoma, tumor tissue of dogs is therefore, among other reasons, much better suitable than tissue from rats or cells cultivated in the laboratory. “Importantly, however, we don’t view our dog patients as test subjects for cancer research,” Markkanen says. “But they can help us to better understand breast carcinoma in both dogs and humans and fight it more effectively.”

Source:  University of Zurich media statement

Training of explosive-detecting dogs

With a sense of smell much greater than humans, dogs are considered the gold standard for explosive detection in many situations. But that doesn’t mean there isn’t room for improvement.

In a study appearing in the journal Analytical Chemistry, scientists report on a new, more rigorous approach to training dogs and their handlers based on real-time analysis of what canines actually smell when they are exposed to explosive materials.

Vapor analysis training

New training techniques based on real-time analysis of what a dog smells could improve explosives detection. Credit: wellphoto/Shutterstock.com

Explosives are often used in terrorist attacks. Dogs trained to detect odors emanating from TNT, nitroglycerin and other explosives are a crucial part of the first-line defense against these incidents. But delivering low-concentration vapor during training sessions is a challenging task. Cross-contamination of training materials with samples from different explosives can skew results and confuse both dogs and handlers. To address these concerns, Ta-Hsuan Ong and colleagues sought to better understand the components within explosive odors that cue a dog’s reaction.

The researchers developed a real-time vapor analysis mass spectrometer to more accurately measure the vapor plumes from explosives that trigger a canine response.

In field trials, they used the device and found that some mistakes the dogs made were indeed correct identifications. For example, some “blanks” were used that were ostensibly prepared without explosive material, but the dogs indicated an explosive was present. When the researchers used the mass spectrometer on such blanks, they found evidence of explosive vapors, indicating cross contamination occurred or other interferents were present.

Based on these findings, the researchers suggest that use of real-time vapor analysis could help differentiate canine mistakes from cross contamination and other issues during training.

Source:  American Chemical Society

Quantifying the Effects of Service Dogs for Veterans with PTSD

veteran with dog

 

Researchers from the Purdue University College of Veterinary Medicine’s Center for the Human Animal Bond will analyze the influence service dogs have on the lives of military veterans suffering from post-traumatic stress disorder (PTSD) in a unique clinical trial.

According to the United States Veterans Administration, 22 veterans commit suicide each day, and at least 40 percent have been diagnosed with PTSD. The rate could be even higher, as many cases of PTSD go undiagnosed.

Previous studies have suggested that individuals who bond with their pet dogs exhibit elevated levels of oxytocin – sometimes referred to as the “cuddle hormone” because it sparks emotional responses that contribute to relaxation and trust. Additionally, the National Center for PTSD claims dogs can encourage veterans to communicate more through commands and training, and prompt them to spend more time outdoors and meet new people.

These benefits support anecdotal reports that show an increase in the prevalence of service dogs for individuals with PTSD, but scientific evidence examining this growing trend and its effects on PTSD patients is still lacking.

“Many veterans are increasingly seeking complementary interventions for PTSD, including service dogs,” stated Maggie O’Haire, lead researcher and assistant professor of human-animal interaction at Purdue. “Yet, even with the well-meaning intentions of service dog organizations that are working to meet the demand, our systematic review of scientific literature confirms a lack of published, empirical research on the effects that service dogs have on veterans and their spouses.”

To help carry out the study, the research team has partnered with K9s for Warriors – one of the nation’s leading providers of service dogs to military vets suffering from a variety of conditions including PTSD, traumatic brain injuries, or sexual trauma as a result of service post-9/11.

The team hopes to determine what sort of PTSD symptom changes veterans may experience as a result of having a service dog, as well as any effects on social functioning and physiological biomarkers.

According to a university release, standardized survey instruments and objective measures of physiology will be used to track stress and functioning. The researchers will also use a novel ecological momentary assessment protocol to capture the role and function of the dogs in everyday life.

The results will be the first evidence-based data to be published that quantitatively identifies the roles and effects of service dogs for military veterans with PTSD.

The study is unique because it applies research methodology and evidence-based science to an area that has typically relied on emotion, according to O’Haire.

“Without scientifically sound studies that establish proof-of-concept for the therapeutic efficacy of PTSD service dogs, this animal-assisted intervention strategy will continue to be minimized as an unsupported and potentially unsound practice, despite anecdotal reports that the dogs may have a significant impact,” added O’Haire.

Source:  www.laboratoryequipment.com

Sharing your bed with your pet (or other humans)

About half of all pet owners share their beds or bedrooms with their pets at night. Although this has been the case through the ages, remarkably few studies have been done about the benefits and drawbacks of this practice.

In an article in Springer’s journal Human Nature, the authors argue that society regards both human-animal and adult-child co-sleeping with the same unnecessary apprehension. These concerns should, however, be set aside because both practices have their benefits, says lead author Bradley Smith of Central Queensland University in Australia.

sleeping together

Sleeping arrangements between humans have evolved over time and across cultures. In medieval Europe, for instance, sleep was a public and communal affair. It was not uncommon to receive visitors in the bedroom, or for many people to sleep in the same bed. Sleeping with others was a way to increase personal security, conserve resources, and generate warmth. Sleeping with children from birth is still the norm in many cultures, for instance in Egypt and among indigenous cultures in unindustrialized populations. Intergenerational co-sleeping is generally more prevalent in collectivist Asian countries than in contemporary, individualistic or industrialized Western cultures.

In the West, sleep is nowadays regarded as an individual and private experience that helps the body and mind to optimally rest and recuperate. The normative shift from sleep as a public and social affair to a private one arose through a complex “civilizing” process starting in the Victorian era. Social norms and rules began to dictate that each person should sleep in a single bed, in a private place away from public view, and wear appropriate sleeping attire. This gradually introduced the concept of the private bedroom and private sleep to many social classes.

In their paper, Smith and his co-authors use dogs as an example of human-animal co-sleeping. They compare human-canine sleeping with adult-child co-sleeping and argue that both forms of co-sleeping share common factors for establishment and maintenance, and have similar advantages and disadvantages.

According to the Australian researchers, current apprehension about human-animal co-sleeping and bed sharing between parents and their children focuses too much on possible negative aspects or consequences, such as poor health, impaired functioning, the development of problematic behavior, and even sexual dysfunction.

“Apart from its clear reproductive function for the survival of the species, as well as physiological support for the quality and quantity of sleep that are essential to individual health and well-being, co-sleeping fulfils basic psychological needs and reinforces and maintains social relations,” highlights Smith. “Throughout history, humans have shared their sleeping spaces with other humans and other animals.”

“We propose that human-animal and adult-child co-sleeping should be approached as legitimate and socially relevant forms of co-sleeping,” says Smith, who believes that more research should be done on human-animal co-sleeping practices. “Moreover, a comprehensive understanding of human-animal co-sleeping has significant implications for human sleep, human-animal relations, and animal welfare.”

Reference: Smith, Bradley P. et al. (2017). A Multispecies Approach to Co-Sleeping: Integrating Human-Animal Co-Sleeping Practices into Our Understanding of Human Sleep, Human Nature, DOI: 10.1007/s12110-017-9290-2

Source:  Springer publishing media statement

Dogs can adopt the perspective of humans

Humans are able to interpret the behaviour of others by attributing mental states to them (and to themselves). By adopting the perspectives of other persons, they can assume their emotions, needs and intentions and react accordingly.

In the animal kingdom, the ability to attribute mental states (Theory of Mind) is a highly contentious issue. Cognitive biologists from the Messerli Research Institute of the University of Veterinary Medicine Vienna could prove with a new test procedure that dogs are not only able to identify whether a human has an eye on a food source and, therefore, knows where the food has been hidden. They can also apply this knowledge in order to correctly interpret cues by humans and find food they cannot see themselves.

This perspective taking ability is an important component of social intelligence. It helps dogs to cope with the human environment. The results have been published in the journal Animal Cognition.

 

The so-called Theory of Mind describes the ability in humans to understand mental states in conspecifics such as emotions, intentions, knowledge, beliefs and desires. This ability develops in humans within the first four or five years of life while it is usually denied in animals. Indications that animals can understand mental states or even states of knowledge of others have only been found in apes and corvids so far. Dogs have been tested several times, but the results were poor and contradictory.

With a new experimental approach, cognitive biologists from the Messerli Research Institute could now provide solid evidence for dogs being able to adopt our perspective. By adopting the position of a human and following their gaze, dogs understand what the human could see and, consequently, know.

This ability to ascribe knowledge is only a component of a full-blown Theory of Mind, but an important one.

Identifying the right informant

The so-called Guesser-Knower paradigm is a standard test in research into the attribution of knowledge to others. This experiment involves two persons: a “Knower” who hides food, invisibly for the dog, in one of several food containers or knows where somebody else has hided it, and a “Guesser”. The Guesser has either not been in the room or covered her eyes during the hiding of the food. A non-transparent wall blocks the animals’ view of the food being hidden. After that, the two humans become informants by pointing to different food containers.

The Knower always points to the baited container and the Guesser to another one. All containers smell of food. “To get the food, the dogs have to understand who knows the hiding place (Knower) and who does not and can, therefore, only guess (Guesser). They must identify the informant they can rely on if they have to decide for one food container,” said principal investigator Ludwig Huber. In approximately 70 per cent of the cases the dogs chose the container indicated by the Knower – and thus were able to successfully accomplish the test. This result was independent of the position of the food container, the person acting as the Knower and where the Guesser was looking.

Eye on hidden food source

Dogs are able to identify the human having an eye on a hidden food source. (Photo: Ludwig Huber/Vetmeduni Vienna)

Dogs can adopt human perspectives

The only aim of this test series, however, was to independently confirm a study carried out in New Zealand. Clear evidence of dogs being able to adopt our perspective and take advantage of it was provided in a new test developed by the team, the so-called “Guesser looking away” test.

In this new experiment, a third person in the middle hides the food. This person does not give cues later on. The potential informants were kneeing left and right of this hider and looked to the same side and slightly down. Thus, one of the two persons looked towards the baiter, the other person looked away. “This means that the tested dogs, in order to get the food, had to judge who is the Knower by adopting the informants’ perspectives and following their gazes,” explained Huber. Even in this test, which is very difficult for the animals, approximately 70 per cent of the trials had been mastered.

Adopting the human perspective leads to invisible food

Being able to adopt the perspective of a human does, however, not require the ability to understand intentions or wishes. “But the study showed that dogs can find out what humans or conspecifics can or cannot see,” explained Huber. “By adopting the positions of humans and following their gazes geometrically, they find out what humans see and, therefore, know – and consequently whom they can trust or not.”

In similar experiments, chimpanzees and few bird species such as scrub jays and ravens were able to understand the state of knowledge and also the intentions of conspecifics and modify their own behaviour accordingly. For dogs, there have only been specualtions and vague indications so far. But dogs understand our behaviour very well, for example our degree of attention. They can learn from directly visible cues such as gestures or gazes. Thus, they are able to find food even if their view of it has been blocked. “The ability to interpret our behaviour and anticipate our intentions, which has obviously developed through a combination of domestication and individual experience, seems to have supported the ability to adopt our perspective,” said Huber. “It still remains unclear which cognitive mechanisms contribute to this ability. But it helps dogs to find their way in our world very well.”

Source:  University of Veterinary Medicine, Vienna media release