Study suggests early-life exposure to dogs may lessen risk of developing schizophrenia

Findings do not link similar contact with cats to either schizophrenia or bipolar disorder

Johns Hopkins Medicine

Ever since humans domesticated the dog, the faithful, obedient and protective animal has provided its owner with companionship and emotional well-being. Now, a study from Johns Hopkins Medicine suggests that being around "man's best friend" from an early age may have a health benefit as well -- lessening the chance of developing schizophrenia as an adult.
And while Fido may help prevent that condition, the jury is still out on whether or not there's any link, positive or negative, between being raised with Fluffy the cat and later developing either schizophrenia or bipolar disorder.
"Serious psychiatric disorders have been associated with alterations in the immune system linked to environmental exposures in early life, and since household pets are often among the first things with which children have close contact, it was logical for us to explore the possibilities of a connection between the two," says Robert Yolken, M.D., chair of the Stanley Division of Pediatric Neurovirology and professor of neurovirology in pediatrics at the Johns Hopkins Children's Center, and lead author of a research paper recently posted online in the journal PLOS One.
In the study, Yolken and colleagues at Sheppard Pratt Health System in Baltimore investigated the relationship between exposure to a household pet cat or dog during the first 12 years of life and a later diagnosis of schizophrenia or bipolar disorder. For schizophrenia, the researchers were surprised to see a statistically significant decrease in the risk of a person developing the disorder if exposed to a dog early in life. Across the entire age range studied, there was no significant link between dogs and bipolar disorder, or between cats and either psychiatric disorder.
The researchers caution that more studies are needed to confirm these findings, to search for the factors behind any strongly supported links, and to more precisely define the actual risks of developing psychiatric disorders from exposing infants and children under age 13 to pet cats and dogs.
According to the American Pet Products Association's most recent National Pet Owners Survey, there are 94 million pet cats and 90 million pet dogs in the United States. Previous studies have identified early life exposures to pet cats and dogs as environmental factors that may alter the immune system through various means, including allergic responses, contact with zoonotic (animal) bacteria and viruses, changes in a home's microbiome, and pet-induced stress reduction effects on human brain chemistry.
Some investigators, Yolken notes, suspect that this "immune modulation" may alter the risk of developing psychiatric disorders to which a person is genetically or otherwise predisposed.
In their current study, Yolken and colleagues looked at a population of 1,371 men and women between the ages of 18 and 65 that consisted of 396 people with schizophrenia, 381 with bipolar disorder and 594 controls. Information documented about each person included age, gender, race/ethnicity, place of birth and highest level of parental education (as a measure of socioeconomic status). Patients with schizophrenia and bipolar disorder were recruited from inpatient, day hospital and rehabilitation programs of Sheppard Pratt Health System. Control group members were recruited from the Baltimore area and were screened to rule out any current or past psychiatric disorders.
All study participants were asked if they had a household pet cat or dog or both during their first 12 years of life. Those who reported that a pet cat or dog was in their house when they were born were considered to be exposed to that animal since birth.
The relationship between the age of first household pet exposure and psychiatric diagnosis was defined using a statistical model that produces a hazard ratio -- a measure over time of how often specific events (in this case, exposure to a household pet and development of a psychiatric disorder) happen in a study group compared to their frequency in a control group. A hazard ratio of 1 suggests no difference between groups, while a ratio greater than 1 indicates an increased likelihood of developing schizophrenia or bipolar disorder. Likewise, a ratio less than 1 shows a decreased chance.
Analyses were conducted for four age ranges: birth to 3, 4 to 5, 6 to 8 and 9 to 12.
Surprisingly, Yolken says, the findings suggests that people who are exposed to a pet dog before their 13th birthday are significantly less likely -- as much as 24% -- to be diagnosed later with schizophrenia.
"The largest apparent protective effect was found for children who had a household pet dog at birth or were first exposed after birth but before age 3," he says.
Yolken adds that if it is assumed that the hazard ratio is an accurate reflection of relative risk, then some 840,000 cases of schizophrenia (24% of the 3.5 million people diagnosed with the disorder in the United States) might be prevented by pet dog exposure or other factors associated with pet dog exposure.
"There are several plausible explanations for this possible 'protective' effect from contact with dogs -- perhaps something in the canine microbiome that gets passed to humans and bolsters the immune system against or subdues a genetic predisposition to schizophrenia," Yolken says.
For bipolar disorder, the study results suggest there is no risk association, either positive or negative, with being around dogs as an infant or young child.
Overall for all ages examined, early exposure to pet cats was neutral as the study could not link felines with either an increased or decreased risk of developing schizophrenia or bipolar disorder.
"However, we did find a slightly increased risk of developing both disorders for those who were first in contact with cats between the ages of 9 and 12," Yolken says. "This indicates that the time of exposure may be critical to whether or not it alters the risk."
One example of a suspected pet-borne trigger for schizophrenia is the disease toxoplasmosis, a condition in which cats are the primary hosts of a parasite transmitted to humans via the animals' feces. Pregnant women have been advised for years not to change cat litter boxes to eliminate the risk of the illness passing through the placenta to their fetuses and causing a miscarriage, stillbirth, or potentially, psychiatric disorders in a child born with the infection.
In a 2003 review paper, Yolken and colleague E. Fuller Torrey, M.D., associate director of research at the Stanley Medical Research Institute in Bethesda, Maryland, provided evidence from multiple epidemiological studies conducted since 1953 that showed there also is a statistical connection between a person exposed to the parasite that causes toxoplasmosis and an increased risk of developing schizophrenia. The researchers found that a large number of people in those studies who were diagnosed with serious psychiatric disorders, including schizophrenia, also had high levels of antibodies to the toxoplasmosis parasite.
Because of this finding and others like it, most research has focused on investigating a potential link between early exposure to cats and psychiatric disorder development. Yolken says the most recent study is among the first to consider contact with dogs as well.
"A better understanding of the mechanisms underlying the associations between pet exposure and psychiatric disorders would allow us to develop appropriate prevention and treatment strategies," Yolken says.

First study on human-grade dog food says whole, fresh food is highly digestible

University of Illinois College of Agricultural, Consumer and Environmental Sciences

IMAGE: A University of Illinois study finds that dog foods formulated with human-grade ingredients are highly digestible. view more 

Credit: JustFoodForDogs

URBANA, Ill. - Pet owners are increasingly treating their "fur-babies" like members of the family. In response, some pet food companies are developing diets that more closely resemble human food, incorporating human-grade meat and vegetable ingredients that pass USDA quality inspections. Until now, little research had been done on these foods. A new study from the University of Illinois shows these diets are not only highly palatable, they are more digestible than originally estimated.
Kelly Swanson, the Kraft Heinz Company Endowed Professor in Human Nutrition in the Department of Animal Sciences and the Division of Nutritional Sciences at Illinois, is a co-author on the Translational Animal Science study. "Of course, you assume that since human-grade ingredients are high quality, the foods should be highly digestible," he says. "But until unbiased researchers actually conduct the testing, these companies are getting questioned by consumers and veterinarians. Are the foods safe? Are they complete and balanced? Basically, are they good?"
The researchers tested six commercial dog foods from JustFoodForDogs, a company that claims to exclusively use USDA-certified ingredients in its diets. Their products, similar to a handful of other niche companies and subsidiaries, are formulated using minimally processed human-edible ingredients, such as rice, carrots, broccoli, chicken, lamb, and others, in a kind of casserole. Each diet is also supplemented with human-quality vitamins and minerals to ensure they qualify as complete and balanced for pets.
The researchers determined the chemical composition of the six diets, as well as their nutrient and amino acid digestibility and energy content. In order to avoid the confounding effects of gut microbial activity, they fed each diet to surgically altered roosters lacking ceca, or microbial pouches. Ultimately, all the diets were highly digestible.
One of the goals was to help determine feeding guidelines for specialized diets like these. Since the diets are more similar to human foods than traditional kibble, Swanson says there are risks in using formulas derived from traditional pet foods.
"Typical pet foods are generally less digestible than human foods - that's why feeding guidelines are different from the USDA nutrition guidelines for humans. But if you apply the traditional dog food guidelines for metabolizable energy to human-grade dog foods, you risk overfeeding because these foods are so nutrient-dense," Swanson says.
Amino acid digestibility was also very high - over 85% for most of the indispensable amino acids - indicating high protein quality. This can translate to low stool volume, welcome news for most dog owners.
Although the study included a single product line, Swanson believes the outcomes are likely to translate to similar pet diets using human-grade ingredients. "Individual foods have to be tested, but our results should apply to other products if they're truly using human-grade ingredients. There might be some small differences, but ultimately, they should still be highly digestible," he says.
Swanson notes that any dog food labeled "complete and balanced" should meet the dietary requirements for the animal. Of course, care must still go into researching each pet food company and ensuring they meet your veterinarian's approval. Foods that use premium ingredients may improve coat quality or stool volume above and beyond the basic requirements. And, Swanson says, they satisfy the growing demographic of pet owners who are looking to achieve long-term wellness for their animals.
Swanson is currently testing the diets, along with similar diets from other companies, in dogs.

Evidence suggests previously unrecognized latex allergies may play role in equine asthma

Morris Animal Foundation

DENVER/December 16, 2019 - Latex exposure could be detrimental to a horse's respiratory health. That's the surprising discovery from Morris Animal Foundation-funded research at the Royal Agricultural University and University of Nottingham. While further investigation is needed, researchers say latex could be among the allergens responsible for causing severe equine asthma (sEA), a serious horse ailment with limited treatment options. The team published their findings in the Nature journal Scientific Reports.
The finding came from a larger study that applied a new, more-comprehensive microarray platform to determine the precise allergens within horses' stable dust that elicit sEA. Researchers tested nearly 400 extracts and proteins associated with the equine environment on blood samples from 138 horses from Switzerland, France, the United States and Canada.
The study revealed several previously suspected allergens, such as pollen, mold and insect proteins, are likely involved in sEA, but the most surprising finding was the implication that natural rubber latex might also play a role. In fact, four of the five most significant allergens associated with sEA were latex proteins. The fifth was a protein from Aspergillus fumigatus, a common fungus previously linked with sEA. Until now, latex had not been tested due to limitations associated with classical allergen assessment methods.
"Research to date has generally implicated fungi and bacteria as the predominant allergens associated with sEA, so this was a little unexpected," said Dr. Samuel White, Senior Lecturer at Nottingham Trent University, and the lead author of the paper. "We would need to learn more about how these allergens affect actual predisposed horses, but avoidance of latex allergens may still be beneficial."
Horses primarily come into contact with natural rubber latex on artificial riding surfaces, like arenas and racetracks. Urbanized environments, which also have higher levels of breathable latex from car tires, have been identified as a risk factor in sEA, as well.
The high level of breathable dust associated with training on artificial surfaces has already been linked with chronic bronchitis, inflammation and oxidative stress in riding instructors, and latex has long been associated with a variety of respiratory conditions in humans.
Severe equine asthma, which closely resembles human asthma, is a debilitating and chronic allergic respiratory condition. Diagnosed in all breeds, it affects 14% of horses in the Northern Hemisphere. When exposed to allergens, these horses can experience inflammation and constriction of the airways, as well as excessive mucus production. sEA also is known as heaves, recurrent airway obstruction and chronic obstructive pulmonary disease.
"This new finding highlights the need to better understand the potential health effects of the environments we expose our horses to," said Dr. Janet Patterson-Kane, Morris Animal Foundation Chief Scientific Officer. "It's crucial that we identify which allergens might cause them distress so we know what to avoid as well as develop appropriate treatments."
The team plans to conduct further research to establish exposure levels of latex in a horse's daily environment and demonstrate the benefit of avoiding latex.
Morris Animal Foundation is funding other studies to address equine asthma. One is investigating if targeting a specific protein is a viable new therapeutic strategy to treat the condition. Another is examining differences in mast cell subtypes found in the airways of heathy and asthmatic horses to help identify better diagnostic and treatment strategies for equine asthma.

'Invisible,' restricted horse racing therapy may leave a trail

---

A treatment called extracorporeal shockwave therapy (ESWT) is used in patients both human and equine to speed healing of injured tendons and ligaments. Using high-pressure sonic waves, ESWT is thought to increase blood flow to the treated area and has been shown to reduce pain over the short term.

In racehorses, however, masking pain can come with a cost: Overworked minor injuries could lead to major ones or even pose a life-threatening risk to both horse and rider.
For that reason, horse racing authorities have banned the use of ESWT for horses within 10 days of a race or sporting event. But the question of how to enforce this "invisible" therapy remained open. Now a team led by Mary Robinson, director of the School of Veterinary Medicine's Equine Pharmacology Research Laboratory, and lab member Jinwen Chen has found that the practice does in fact leave a trail. In a paper in Equine Veterinary Journal, they report finding potential biomarkers of ESWT that, with further testing, could one day be used to enforce the ESWT ban.
"Because it's not a drug -- it's applied to the surface of the skin -- it's just not an easy thing to detect," says Robinson. "After a lot of trial and error, our study was able to measure changes in levels of five inflammatory factors, some of which we could detect up to three weeks after the shockwave therapy."
The attempt to find these biomarkers dates back roughly a decade.
"It was Dr. Lawrence Soma, my predecessor, who said the lab was going to have to look at blood-based or urine-based biomarkers to try to detect shockwave therapy," Robinson notes.
To find the fingerprints that ESWT might leave behind, the researchers tested the therapy on 11 horses kept as a study herd at Penn Vet's New Bolton Center. The researchers collected blood samples from the group of horses, composed of Thoroughbreds and Standardbreds, at several times both before and after each received a single dose of ESWT to a leg.
Over the years, the lab investigated a number of potential biomarkers, molecules that would indicate a horse received ESWT. They zeroed in on 10 pro-inflammatory and anti-inflammatory signaling molecules, called cytokines, which they can measure from the blood using a sensitive test called ELISA, short for enzyme-linked immunosorbent assay.
"We looked a week before giving the shockwave therapy to see if there were any changes in the baseline period, due to changes in time of day or anything else, and didn't see anything we could define as significant," Robinson says. "And in the post-shockwave period we went out to three weeks."
They could not detect changes in five of the cytokines they examined following ESWT. But the other five -- TNF-α, IL1β, IL-1RA, IL-6, and sTLR2 -- did respond. Of those, TNF- α levels were significantly increased through the whole of the post-therapy study period, three weeks.
More study is necessary, Robinson emphasizes, before these biomarkers could be used to assess inappropriate use of ESWT in racehorses. For one, the researchers would like to see if measuring these same molecules in horses that are actively training and racing or that have an acute injury might change their results.
For that, she and her colleagues are actively pursuing follow-up studies to look at these biomarkers and other indicators using a biobank of samples from client-owned animals, including injured and active racehorses, treated at New Bolton Center.
The end goal is to keep the sport safe.
"Shockwave therapy is great as long as people rest the horse after using it," she says. "We are concerned that it's being abused in the racehorse industry and that it could potentially result in breakdowns. That's exactly what we're trying to avoid."

Cats' faces hard to read, except for 'cat whisperers,' research finds

Cats have a reputation for being hard to read, but new research from the University of Guelph has found that some people are veritable 'cat whisperers' who excel at deciphering subtle differences in cats' faces that reveal mood

University of Guelph

IMAGE: Professor Georgia Mason. view more 

Credit: University of Guelph

Cats have a reputation for being hard to read, but new research from the University of Guelph has found that some people are veritable "cat whisperers" who excel at deciphering subtle differences in cats' faces that reveal mood.
Women and those with veterinary experience were particularly good at recognizing cats' expressions -- even those who reported they didn't feel a strong attachment to cats, the large study found.
"The ability to read animals' facial expressions is critical to welfare assessment. Our finding that some people are outstanding at reading these subtle clues suggests it's a skill more people can be trained to do," said Prof. Lee Niel, who led the study with Prof. Georgia Mason, both from U of G's Campbell Centre for the Study of Animal Welfare.
The only research so far on readings cats' faces has focused on expressions of pain. "This study is the first to look at the assessment of a wider range of negative emotional states in animals, including fear and frustration, as well as positive emotional states," said Mason.
Published recently in the November issue of Animal Welfare, the study recruited more than 6,300 people from 85 countries who were asked to watch 20 short online videos of cats from a collection of 40 videos, gleaned mostly from YouTube, and complete online questionnaires.
The videos showed cats experiencing either positive emotional states (situations the cats had sought out, such as being petted or given treats), or in negative states (such as experiencing health problems or being in situations that made them retreat or flee). Each video was focused on the cat's face -its eyes, muzzle and mouth. None of the cats showed expressions of fear, such as bared fangs or flattened ears, since these facial expressions are already widely understood.
Participants were asked to judge whether each cat was in a positive state, a negative one, or if they weren't sure.
Most participants found the test challenging. Their average score was 12 out of 20 -- somewhat above chance. But 13 percent of the participants performed very well, correctly scoring 15 or better -- a group the researchers informally called "the cat whisperers."
These people were more likely to be women than men, and more likely to be veterinarians or vet technicians. Younger adults also generally scored better than older adults.
"The fact that women generally scored better than men is consistent with previous research that has shown that women appear to be better at decoding non-verbal displays of emotion, both in humans and dogs," said Mason, who worked on the study along with post-doctoral researchers Jenna Cheal and Lauren Dawson.
Surprisingly, being a cat lover made no difference at all, since reporting a strong attachment to cats did not necessarily result in a higher score.
The finding that some people are skilled at reading cats' faces suggests that others could be trained to do so as well.
"This is important to be able to do because it could help strengthen the bond between owners and cats, and so improve cat care and welfare," said Niel.
To test your own cat-reading abilities, the research team has created a website with details.

###

Contact:
Prof. Georgia Mason
gmason@uoguelph.ca

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

Media Contact
Georgia Mason
gmason@uoguelph.ca

 @uofg
http://www.uoguelph.ca 

---

More on this News Release

Cats' faces hard to read, except for 'cat whisperers,' research finds

University of Guelph

Journal

Animal Welfare

Keywords

• ANIMAL RESEARCH/RIGHTS
• BIOLOGY
• MEDICINE/HEALTH
• PETS/ETHOLOGY
• PETS/ETHOLOGY
• ZOOLOGY/VETERINARY SCIENCE

Multimedia

Georgia Mason, University of Guelph (IMAGE)

Lee Niel, University of Guelph (IMAGE)

Original Source

https://news.uoguelph.ca/2019/12/cats-faces-hard-to-read-except-for-cat-whisperers-u-of-g-research-finds/

Related Journal Article

http://dx.doi.org/10.7120/09627286.28.4.519

---

More in Biology

• Smarter strategies University of California - Santa Barbara
• Most complete commercial sugarcane genome sequence has been assembled Fundação de Amparo à Pesquisa do Estado de São Paulo
• Climate change and human activities threatens picky penguins University of Saskatchewan
• Oat pathogen defence discovery marks an important milestone John Innes Centre

View all in Biology 

---

Trending News Releases

• Making higher-energy light to fight cancer University of California - Riverside
• Svalbard reindeer populations rebounding from centuries of hunting Norwegian University of Science and Technology
• MBL team images the bacterial hitchhikers on plastic trash in ocean Marine Biological Laboratory
• Drone images show Greenland ice sheet becoming more unstable as it fractures University of Cambridge

View all latest news releases 

---

Copyright © 2019 by the American Association for the Advancement of Science (AAAS)

• Latest News Releases RSS Feed
• All EurekAlert! RSS Feeds
• @EurekAlert
• facebook.com/EurekAlert

• Help / FAQ
• Disclaimer
• Privacy Policy
• Terms & Conditions
• Contact EurekAlert!

FDA announces dog food brands that could cause heart failure

The U.S. Food and Drug Administration has released a list of pet food brands that they say could cause congestive heart failure in dogs.
In July 2018, the FDA first alerted the public about an investigation that found a possible link between dilated cardiomyopathy (DCM) and dogs eating certain types of pet food.
Canine DCM is described as the disease of a dog’s heart muscle, can often result in congestive heart failure.
Breeds that are typically affected are large and giant breed dogs, according to the FDA. However, many of the 524 cases of DCM reported to the FDA have included smaller breeds of dogs, suggesting a lack of a genetic connection.
In many cases, food linked to DCM was in dry form and contained ingredients including peas, lentils, potatoes, and sweet potatoes. Many others were grain-free.
The following dog food brands were named the most in reported DCM cases, according to the FDA:

• Acana: 67
• Zignature: 64
• Taste of the Wild: 53
• 4Health: 32
• Earthborn Holistic: 32
• Blue Buffalo: 31
• Nature’s Domain: 29
• Fromm: 24
• Merrick: 16
• California Natural: 15
• Natural Balance: 15
• Orijen: 12
• Nature’s Variety: 11
• NutriSource: 10
• Nutro: 10
• Rachael Ray Nutrish: 10

The FDA is urging pet owners to work with their veterinarians, who have the ability to consult a board-certified veterinary nutritionist, to obtain the most appropriate dietary advice.

Clay as a feed supplement in dairy cattle has multiple benefits

Dairy producers frequently add clay as a feed supplement to reduce the symptoms of aflatoxin and subacute ruminal acidosis (SARA) in lactating cows. In a new study from the University of Illinois, researchers show that clay can also improve the degradability of feedstuffs.
"Farmers are giving this clay, but they want to know if the corn silage or hay the cow is eating is affected. We found that yes, the clay is changing the way the cow degrades feedstuffs," says Phil Cardoso, associate professor in the Department of Animal Sciences at Illinois and co-author of the Animal Feed Science and Technology study.
Cardoso and his team tested the degradability of six feedstuffs - dried alfalfa hay, grass hay, wet brewer's grains, ground corn, corn silage, and soybean meal - along with no added clay, 1%, or 2% of dietary dry matter.
The researchers placed the feedstuffs into mesh bags and inserted them directly into the rumen through a cannula or fistula, a surgically installed portal that allows the contents of the rumen to be sampled for research purposes. The bags were then drawn out at multiple time intervals (two hours to four days) and analyzed.
"There were some differences in how the feedstuffs degraded over time. When clay was added to grass hay at 2% of dietary dry matter, the digestibility and usage of the fat in that material was maximized. It's better. And we didn't see a decline in degradability of the other feedstuffs, either," Cardoso says. "Overall, to maximize the benefits of clay, we'd recommend adding it at 1 to 2% of dietary dry matter."
Cardoso's previous research has shown that multiple types of clay are effective in handling aflatoxin, a toxic substance produced by fungal contaminants on feed. When the toxin is bound up by the clay, it is simply excreted from the cow's body, rather than being absorbed in the bloodstream. And a 2018 study by Cardoso's team showed that aluminosilicate clay improved cows' immune function and reduced liver inflammation during an aflatoxin challenge.
Cardoso says, "From all of our work on this, I can tell producers whenever they are facing the risk of aflatoxin, they should consider using clay without worrying about it binding other minerals or hindering forage digestibility. Rather, we've shown digestibility could increase. Of course, it's important to ensure the specific clay product has been tested."
Clay's benefits don't stop there. Because the material attracts and binds positively charged ions, clay can make the rumen less acidic. This is important particularly given the popularity of increasing grain concentrates in TMR feed, which can lead to SARA. In a 2016 study from Cardoso's group, cows challenged with excess wheat in a TMR diet produced more and higher-quality milk and had higher rumen pH when fed bentonite clay at 2% of dietary dry matter.

"Basically, clay has all these benefits: It reduces aflatoxin toxicity, works as a pH buffer, and also improves the degradability of some feedstuffs," Cardoso says. "Producers should know this."