OSU researchers study which is a healthier option for pet diets

Thursday, October 24, 2024

Media Contact: Taylor Bacon | Public Relations and Marketing Coordinator | 405-744-6728 | taylor.bacon@okstate.edu

In a world where consumers are constantly seeking the healthiest options for skin care, household cleaners and their own diets, they are also seeking the healthiest diet possible for their pets. 

Many pet owners have attempted feeding their dogs nontraditional foods such as raw meat-based diets. However, little is known about the effects of these foods on animal health and there are several potential risks owners should consider when selecting their pets’ diets. 

Oklahoma State University researchers investigated the effect of feeding dogs a kibble or raw meat-based diet on fecal microbiota composition, serum metabolomics and inflammatory markers. 

It’s no surprise dry kibble has historically dominated the market because of its ease of use, shelf stability and its formulation to meet nutritional standards. Conversely, dry kibble also has some potential drawbacks that lead pet owners to pursue alternative options. Traditional pet foods are processed using heat treatments designed to improve digestibility, extend shelf life and eliminate pathogens, but those same high temperatures may also affect the bioavailability of some nutrients.

An alternative is grain-free, boutique dog foods. Consumers once believed they were a more wholesome diet choice. However, researchers have found conflicting information, which has sparked a lot of debate on the topic. 

This has led pet owners to implement fresh, dehydrated and freeze-dried raw meat-based diets. They cite increased digestibility of nutrients, less chance of contaminants and the belief it reduces chronic, inflammatory conditions such as allergies, avoids gastrointestinal disorders, improves dental health and reduces fecal output.

However, they also present potential risks to both pets and pet owners. Researchers found there has been an increased presence of pathogenic bacteria in raw pet food, with case reports of serious foodborne diseases in humans handling raw pet food as well as enteric diseases in pets consuming these products. Malnutrition is another issue because owners don’t always properly formulate home-designed diets. 

One of the researchers involved in the study was Dr. Lara Sypniewski, OSU College of Veterinary Medicine clinical associate professor in small animal primary care. Sypniewski also holds the Henthorne Clinical Professorship in Small Animal Medicine, which provided some of the study’s funding. 

Sypniewski said nontraditional diets are becoming popular among pet owners at the OSU Veterinary Medical Teaching Hospital and veterinarians do not have enough research data to help clientele make educated decisions about feeding raw diets. 

Fifty-five dogs with a history of being fed either a raw-meat-based diet or a kibble diet for longer than one year were included in the study. At the start, Sypniewski physically examined each dog to confirm general health and collected samples to establish baseline laboratory values. Dogs in the study were fed a standardized diet of a single brand of either kibble or raw-meat-based diets for 28 days. 

On day 28, the dogs returned for another physical examination and sample collection by Sypniewski. Serum and fecal samples were collected to analyze microbiota, metabolomics and inflammatory markers. 

Sypniewski said results showed higher protein diets, those without plant-based carbohydrates, impact the fecal microbiome population. This was expected among the researchers based on prior studies.

“Although microbiome populations were different, there was no significant difference in the systemic inflammatory markers evaluated, but we have to remember all dogs were healthy to begin with,” Sypniewski said.

The biggest difference Sypniewski said they found was the intestinal markers of inflammation, which were significantly higher in dogs fed raw food rather than kibble.

“Intestinal alkaline phosphatase (IAP) is a protective enzyme which was much higher in raw fed dogs,” Sypniewski said. “Dogs with chronic enteric disease, or gastrointestinal disease, have reduced IAP. We theorize that the IAP levels in raw-fed dogs could be a sign they have reduced susceptibility to inflammatory conditions.

“Fecal immunoglobulins (fecal IgA, IgG), which are responsible for the mucosal immunity and steady-state health in the gut, were increased. Fecal IgA responds to pathogens and allergens. It is a protective immunoglobulin and important for immune tolerance and keeping the commensal bacteria local to the lumen of the gut.” 

In dogs, an increased fecal IgA is good because Sypniewski said low levels can be associated with inflammatory and autoimmune disease. 

“Overall, I think this study offers people the opportunity to start with a discussion regarding a less processed or raw diet with their veterinarian,” Sypniewski said. “I believe this information can offer another feeding option for dogs with chronic inflammatory GI disease as it may improve gut homeostasis.” 

This study represents a collaborative effort across OSU’s campus. It involves members of OSU CVM, the Ferguson College of Agriculture, and the OSU College of Arts and Sciences. 

“Collaborative impacts can never be understated,” Sypniewski said. “Bringing together a diverse group of people, each with their own expertise and experience, only adds to the possibilities of new knowledge.” 

Just in the CVM alone, there was plenty of collaboration between faculty members and hospital staff.

“The hospital is instrumental in allowing us to complete clinical research under one roof,” Sypniewski said. “Without the help of our veterinary nurses and research personnel, this project never would have been possible.”

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Photos By: Taylor Bacon, Phil Shockley, and Ellie Piper

Story By: Taylor Bacon | Vet Voices Magazine