Heads up: A report from the AAVN Clinical Nutrition & Research Symposium

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The American Academy of Veterinary Nutrition (AAVN) held this year's annual symposium on June 3 in Phoenix, Arizona. The AAVN's objectives include sharing information relating to animal nutrition, promoting interest and research in animal nutrition, and creating relationships between veterinary professionals and other individuals in the field of animal nutrition. The symposium is a culmination of those objectives and includes a mix of research abstract presentations-published annually in the Journal of Animal Physiology and Animal Nutrition-and guest speakers. This year we welcomed nine oral abstract presentations, 16 poster presentations and four guest speakers.

Lentils, DCM and taurine

Research is starting to emerge investigating the potential link between diet and dilated cardiomyopathy (DCM) in dogs. Researchers from the University of Illinois at Urbana-Champaign investigated the relationship between a high inclusion of pulses (the dried seeds of legumes) and taurine status in dogs.¹ In a controlled environment, dogs were assigned to one of two diets: one containing approximately 45% green lentils and one with a primary protein source of poultry byproduct meal. Over 90 days, no significant differences were found in taurine or amino acid concentrations such as plasma methionine between the two diets. These results suggest that inclusion of about 45% green lentils in a dog's diet does not affect circulating taurine concentrations.

How storage affects microbiome

The winner of the annual AAVN & Waltham Student Research Award, Ching-Yen Lin from the University of Illinois, demonstrated the importance of collection and storage methods when it comes to canine microbiome research.² Canine fecal samples were collected and stored under different conditions using a novel microbiome stabilization method or unstabilized at room temperature. Changes in diversity and abundance of dominant bacterial phyla and genera were documented between stabilized and unstabilized samples, suggesting that the storage method is important to maintain data integrity. This study is significant given the abundance of groups investigating the microbiome in veterinary medicine.

Nutrients in home-prepared diets

Home-prepared diets for pets are becoming increasingly popular not only in the United States but in many other countries as well. Investigators from the University of São Paulo in Brazil evaluated home-prepared diets whose recipes for healthy dogs and cats were published online in Portuguese.³ Seventy-five canine and 25 feline diets were selected for nutrient evaluation. None of the diets met 2018 nutritional guidelines established by the European Pet Food Industry Federation (FEDIAF), with the majority having three or more nutrient deficiencies. Although no diets supplied all recommended nutrients, those with more ingredients did have an improved nutritional profile. This research further emphasizes that pet owners interested in preparing food at home for their pets should consult with veterinary professionals specifically trained with credentials to balance home-prepared diets.

The marketing of meat

Mark Finke, PhD, a pet food formulator with many years of experience, presented a guest lecture titled, “Market Driven Pet Food Ingredients: The Formulator's Perspective.” In this talk he discussed how the market drives the demands of commercial pet food and what the formulators do to meet these demands. One such example is the marketing of “meat as the first ingredient.” He points out that the ingredient list, presented in descending order by item weight, can be manipulated by the formulator to improve consumer perception of the diet. This includes using multiple carbohydrate sources with similar nutrient profiles or splitting a carbohydrate into its different fractions, thus allowing each ingredient to appear farther down the ingredient list.

Additionally, ingredients with equal weight can be listed in the order preferred by the formulator. For example, if chicken, potato and peas have equal weight in a diet formulation, the chicken can be listed first. Formulators must also be familiar with novel ingredients used in pet food formulations. This includes potential hazards and nutrients provided by the new ingredient. Dr. Finke also reminded the audience that pet food companies get what they inspect, not what they expect, when it comes to working with suppliers and raw materials.

More on DCM and diet

The rise of DCM in dogs and its relationship to diet has created much concern and interest among veterinary professionals and animal nutrition scientists. The cause of diet-associated DCM in dogs remains unknown. Although initially thought to be related to taurine, the majority of cases reported to the FDA are not taurine-deficient. Lisa Freeman, DVM, PhD, DACVN, presented a comprehensive review of the potential link between diet and the development of DCM in the dog. She reminded the audience there may be other nutritional factors contributing to the development of DCM, including thiamine, L-carnitine, copper, choline, vitamin E, selenium and so on.

As veterinarians and pet owners sort through information provided by the FDA, we should remember that there may be bias in the data, including underreporting of cases involving breeds typically associated with genetic or primary DCM, such as Doberman pinschers, or overreporting of certain breeds, such as golden retrievers, where there is increased awareness among pet owners. Veterinarians and pet owners are encouraged to report all cases of dogs diagnosed with DCM to the FDA to help with the investigation.

AAFCO on hemp, buffalo

Dave Dzanis, DVM, PhD, DACVN, of Regulatory Discretion Inc., delivered a regulatory report that included updates from the Association of American Feed Control Officials (AAFCO). While hemp-based pet products are becoming more common, AAFCO has not defined hemp-based products as an ingredient for animal feed nor has the FDA approved hemp-based products for inclusion in pet foods. Consumers may also be familiar with buffalo as an ingredient in pet food. What consumers may not realize is that this ingredient is typically water buffalo or other buffalo species, not the American buffalo-technically bison-that may be depicted on the packaging. A working group has been established by AAFCO to better define this ingredient to be more transparent to the consumer. Other updates included pet food labeling modernization efforts and a proposal to revise dog feeding trial protocols to ensure the diets are appropriate for large-breed dogs.

The 20th Annual AAVN Clinical Nutrition & Research Symposium will take place in Baltimore, Maryland, on June 10, 2020.  

References

1. Reilly LM, de Godoy MRC. Longitudinal assessment of taurine and amino acid concentration in dogs fed a green lentil diet, in Proceedings. 19th Annual AAVN Clinical Nutrition & Research Symposium. June 5, 2019.

2. Lin C, Cross TL, Doukhanine E, et al. Collection and storage methods affect the microbiome data of canine fecal samples, in Proceedings. 19th Annual AAVN Clinical Nutrition & Research Symposium. June 5, 2019.

3. Pedrinelli V, Zafalon RVA, Rodrigues RBA, et al. Influence of number of ingredients, supplement and vegetarian preparation on composition of homemade diets, in Proceedings. 19th Annual AAVN Clinical Nutrition & Research Symposium. June 5, 2019.

Dr. Martha G. Cline is president of the American Academy of Veterinary Nutrition Executive Board for the 2017-2021 term.