Tag: dogs

Dogs and Owners Match Their Heart Rate Variability

Photo by Pauline Loroy on Unsplash

A study at the University of Jyväskylä showed that the heart rate variability of a dog and its owner adapt to each other during interaction. High heart rate variability is associated with relaxation, while low heart rate variability indicates stimulation. The study, published in Scientific Reports, deepens our understanding of the emotional connection between a dog and its owner, including its underlying physiological mechanisms.

Emotional connection enhances interaction in human relationships. Emotional synchronisation in the interaction between a child and a parent is essential for affective attachment. The relationship between a dog and its owner is also based on attachment, but little is known about its physiological mechanisms.

The heart rate variability of a dog and its owner adapt to each other

In a study conducted at the University of Jyväskylä, at the Department of Psychology and Jyväskylä Centre for Interdisciplinary Brain Research, it was found that the heart rate variability of a dog and its owner are interconnected during interaction. Heart rate variability, in other words, the variation in the heartbeat intervals, indicates the state of the autonomic nervous system. High heart rate variability is associated with a state of relaxation and recovery, while low heart rate variability indicates stimulation or strain, such as stress during an exam or sport performance. In this study, the owner’s high heart rate variability was connected to the dog’s high heart rate variability, and vice versa. In addition, the physical activity levels of a dog and its owner mutually adapted to each other during the study. 

Different connections for activity and heart rate variability

The connections of heart rate variability and activity levels between a dog and its owner were monitored during specific interaction tasks. Both heart rate and activity level were interconnected between dogs and their owners, but at different times. During free-form resting periods, the owner’s high heart rate variability was connected to the dog’s high heart rate variability. In other words, when the owner was relaxed the dog was also relaxed. Moreover, the owner’s and dog’s activity levels were similar during the given tasks, such as playing. Although it is known that physical activity has an impact on heart rate, the strongest connections of these variables between dog and owner were found in different situations and do not fully explain each other. This suggests that the connection in heart rate variability reflects the synchrony of emotional state rather than of activity levels.

“The interconnection in heart rate variability between the dog and its owner during resting periods may be explained by the fact that in those instances there were no external tasks, but the counterparts could react more to each other’s state in a natural way,” says Doctoral Researcher Aija Koskela. 

Owner’s temperament is connected to the dog’s heart rate variability

The study also investigated various background factors for the interconnection of the heart rate variability of the dog and its owner. Bigger dogs had higher heart rate variability. In addition, the dog’s high heart rate variability was also explained by the owner’s negative affectivity, a temperament trait that reflects the person’s tendency to become easily concerned about negative things. This type of owner tends to develop a strong emotional bond with the dog, and therefore the shepherd dogs of this study possibly had a higher sense of safety with these owners. 

The dog also influences the owner

A surprising finding in the study was that the owner’s heart rate variability was best explained by the dog’s heart rate variability, even though also the owner’s activity level and body mass index, which are known to impact heart rate, were taken into account in the analysis.

“We exceptionally investigated both a dog’s and its owner’s heart rate and activity level simultaneously, whereas previous studies have commonly focused either on the human’s or the dog’s perspective,” says the leader of the study, Academy Research Fellow Miiamaaria Kujala. “The challenging research setting gives a better opportunity to investigate interactive aspects.”

This study indicates that the emotional states of dogs and their owners as well as the reactions of their nervous system become partially adapted to each other during interaction. The same mechanisms that strengthen human affective attachment also seem to support the relationship between a dog and its owner. This study deepens our understanding about interaction between species and about the meaning of emotional connection between dogs and humans. 

Interaction research involved dogs bred for cooperation

The study was funded mainly by the Research Council of Finland and the Agria & Svenska Kennelklubben Research Fund. It involved altogether 30 voluntary dog owners with their dogs. The dogs represented breeds refined for cooperating with humans, such as sheep dogs and retrievers. The research findings are in line with previous studies, which have suggested that breeds selected for cooperation are particularly sensitive to react to their owners’ behaviour and personality traits. Next, the project will seek to shed light more specifically on the influential mechanisms involved in this phenomenon.

Source: University of Jyväskylä

Man’s Best Friend Shares Similarities in Genetics of Meningiomas

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Researchers have discovered that meningiomas – the most common type of brain tumour in humans and dogs – are extremely similar genetically. These newly discovered similarities will allow doctors to use a classification system that identifies aggressive tumours in both humans and dogs, while also opening the door for new and exciting collaborations between human and animal medicine. The researchers, from Texas A&M School of Veterinary Medicine & Biomedical Sciences (VMBS), Baylor College of Medicine and Texas Children’s Hospital, published their findings in the scientific journal Acta Neuropathologica.

Until now, the lack of reliable and viable experimental models has been a barrier to understanding the biology of and developing effective treatments for these brain tumours.

“The discovery that naturally occurring canine tumours closely resemble their human counterparts opens numerous avenues for exploring the biology of these challenging tumors,” said Dr. Akash Patel, an associate professor of neurosurgery at Baylor College of Medicine and principal investigator at the Jan and Dan Duncan Neurological Research Institute (Duncan NRI) at Texas Children’s Hospital.

“It also provides opportunities for developing and studying novel treatments applicable to both humans and dogs.”

The study was led by Patel; Dr Jonathan Levine, a VMBS professor and head of the Department of Small Animal Clinical Sciences (VSCS); and Dr Tiemo Klisch, assistant professor at Baylor College of Medicine and principal investigator at Duncan NRI. VSCS assistant professor Dr Beth Boudreau was a key collaborator.

For the project, the team analysed 62 canine meningiomas from 27 dog breeds and discovered that the tumours shared remarkable similarities to the same kinds of tumours when they occur in humans.

This is the largest study to date of the gene expression profiles of canine meningiomas.

Watching the signs

The new discovery was made possible by building on recent work conducted by Patel’s team, as well as previous work by Levine and Boudreau that explored gliomas, another type of brain tumour.

In 2019, Patel and others at Baylor College of Medicine and Texas Children’s Hospital found that they could classify meningiomas in humans into three biologically distinct subtypes – MenG A, B, and C – by analysing their RNA.

The new classification system can predict patient outcomes with greater accuracy than the standard tissue sample analysis.

“Because RNA shows how a tumour’s genes activate, it allows researchers to accurately predict how a tumour will behave – whether it will be aggressive or if it’s going to respond to certain therapies,” Levine said.

“We ended up agreeing to provide Patel with canine tumor samples we had worked years and years to archive, to see if he could isolate the RNA, which is not always easy to do,” Levine said.

“He was able to produce this very robust dataset that showed a similar pattern structure to human tumours. Our team also provided Dr Patel with key clinical outcome data, including responses to certain treatments.”

Onward to clinical trials

Now that the researchers have established a connection between tumors across the two species, they can begin preparations for clinical trials, which can take several years to plan and fund.

“We’re really interested in creating wins for both human and animal medicine,” Levine said.

“For example, we hope to give dog owners access to therapy that’s not available anywhere else in the world through clinical trials. At the same time, that information will also inform the next step of human trials.”

Incidentally, a separate group of researchers from the University of California, Davis, conducted a similar study with matching conclusions about meningiomas in dogs and people and published its work in the same journal.

The two research groups look forward to collaborating in the future to develop tumour treatments for both species.

Source: Texas A&M University

Growing up with Dogs (But not Cats) Protects Against Crohn’s Disease

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Young children who grow up with a dog or in a large family appears to confer some protection later on in life from Crohn’s disease, according to a study presented at Digestive Disease Week® (DDW) 2022.

Crohn’s disease is a common type of inflammatory bowel disease that often develops in young adults, smokers, and those with a close family member who has IBD. Symptoms include diarrhoea, abdominal pain and weight loss. Treatments currently aim to prevent symptom flare-ups through diet modification, medication, and surgery.

“Our study seems to add to others that have explored the ‘hygiene hypothesis’ which suggests that the lack of exposure to microbes early in life may lead to lack of immune regulation toward environmental microbes,” said Williams Turpin, PhD, the study’s senior author and a research associate with Mount Sinai Hospital and the University of Toronto.

Researchers used an environmental questionnaire to collect information from nearly 4300 first-degree relatives of people with Crohn’s disease enrolled in the Crohn’s and Colitis Canada Genetic, Environmental, and Microbial (CCC-GEM) project. Using responses to the questionnaire and historical data collected at the time of recruitment, Dr Turpin and his team analysed several environmental factors, including family size, the presence of dogs or cats as household pets, the number of bathrooms in the house, living on a farm, drinking unpasteurised milk and drinking well water. The analysis also included age at the time of exposure.

The study found that exposure to dogs, especially from ages 5 to 15, was associated with healthy gut permeability and balance between the microbes in the gut and the body’s immune response, which may all help protect against Crohn’s disease. Similar effects were observed with exposure to dogs across all age groups.

“We did not see the same results with cats, though we are still trying to determine why,” Dr Turpin said. “It could potentially be because dog owners get outside more often with their pets or live in areas with more green space, which has been shown previously to protect against Crohn’s.”

Another protective factor seemed to be living with three or more family members in the first year of life, which was associated with microbiome composition later in life. The gut microbiome is believed to play a role in a number of health conditions, such as inflammatory bowel disease, colorectal cancer, diabetes, and high blood pressure.

Dr Turpin and his colleagues hope their findings may assist physicians in asking detailed questions of patients to determine who is at highest risk. However, he noted that the early life environmental factors were assessed by questionnaires, so caution is warranted in interpreting these results due to possible recall bias at recruitment. The reasons dog ownership and larger families appear to provide protection from Crohn’s remain unclear.

Source: Digestive Disease Week

For Alzheimer’s, Old Dogs Can Teach Humans New Tricks

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Researchers have found that quantifiable changes can be measured in dogs suspected of suffering from cognitive decline: an approach that could serve as a model for evaluating cognitive decline progression in, and treatments for, humans with Alzheimer’s disease.

In dogs there is a similar condition to similar to Alzheimer’s disease in humans, canine cognitive dysfunction syndrome (CCDS). In CCDS, cognitive decline is associated with the development of amyloid plaques as well as cortical atrophy. CCDS is also challenging to diagnose. Traditionally, CCDS is diagnosed based on ruling out any obvious physical conditions and an owner’s answers to a questionnaire.

“One problem with the current approach is that questionnaires only capture a constellation of home behaviours,” explained Professor Natasha Olby, co-senior author of the paper. “There can be other reasons for what an owner may perceive as cognitive decline – anything from an undiagnosed infection to a brain tumour.”

Olby and co-senior author Assistant Professor Margaret Gruen, wanted to see if cognitive function could be accurately quantified in dogs.

“Our goal was to bring together multiple tools in order to get a more complete picture of how CCDS presents in dogs,” A/Prof Gruen said.

To accomplish this, they recruited 39 dogs from 15 breeds. All of them were in the senior and geriatric age range, but in good health overall. A dog is considered ‘senior’ if it is in the last 25% of its expected life span based on breed and size, and geriatric beyond that.

The dogs underwent physical and orthopaedic exams, as well as lab work that included a blood test that is a marker of neuronal death. Their owners filled out two commonly used diagnostic questionnaires, and then the dogs participated in a series of cognitive tests designed to assess executive function, memory and attention.

“The approach we took isn’t necessarily designed to be diagnostic; instead, we want to use these tools to be able to identify dogs at an early stage and be able to follow them as the disease progresses, quantifying the changes,” Prof Olby said.

The team found that cognitive and blood test results correlated well with the questionnaire scores, suggesting that a multi-dimensional approach can be used to quantify cognitive decline in aging dogs.

“Being able to diagnose and quantify CCDS in a way that is clinically safe and relevant is a good first step toward being able to work with dogs as a model for Alzheimer’s disease in humans,” Prof Olby said. “Many of the current models of Alzheimers disease – in rodents, for example – are good for understanding physiological changes, but not for testing treatments.”

“Dogs live in our homes and develop naturally occurring disease just like we do,” A/Prof Gruen said. “These findings show promise for both dogs and humans in terms of improving our understanding of disease progression as well as for potentially testing treatments.”

Source: North Carolina State University