Nutrient-gene interactions and their role in complex diseases in dogs

The relationship of feeding patterns and obesity in dogs

The rates of dog obesity are increasing and a greater understanding of feeding patterns is required to combat the problem. This study examined relationships between dietary patterns and caloric intake, and nutrient content of foods fed as it relates to obesity in dogs in the United States. Sixty-one owners and their dogs were enrolled, and lifestyle surveys, food frequencies, and 3-day food records were collected. Significant differences in overall kcal intake per kilogram of body weight were found (p< 0.04). Crude fibre in dog food was positively associated with protein and negatively associated with fat regardless of the dog's weight (p< 0.001). Lean dogs received significantly more crude fibre in relation to overweight dogs regardless of the number of treats they received (p< 0.01), and their diets had greater micronutrient densities (p< 0.03) suggesting that high fibre influences body condition. Additionally, owners who ate nutrient-rich, calorie-poor diets had normal weight dogs, and owners that fed more table scraps had overweight dogs. Regardless of body condition, 59% of dogs received table scraps, which constituted 21% of daily caloric intake. The nutrient density of scraps fed was variable and did not meet National Research Council's recommendations for micronutrient adequacy.

Nutritional therapies to improve health: lessons from companion animals

Companion animals represent an under-utilised resource. The present paper is designed to encourage collaborative studies. Dogs and cats are out-bred animals that are willing to consume a consistent diet for long periods, so are ideal candidates for prospective studies of naturally-occurring disease. In some studies the effect of diet on survival has been substantial. Food restriction, for example, slows the development of osteoarthritis and increases the lifespan of Labrador retrievers by 2 years, protein and P restriction more than doubles the median survival time of dogs and cats with chronic kidney disease and addingn-3 fats and arginine to the diet of dogs with stage 3 lymphoma improves median survival time by one-quarter. Obesity is also very common in both dogs and cats and is also associated with disease as in human subjects. When interpreting these results, however, it is essential to take into account pathophysiological differences among species. Dogs and cats do not display all the characteristics of metabolic disease in human subjects, they metabolise fat well and atherosclerosis and cardiac infarction are uncommon. Such differences should not, however, preclude further study because differences among species often clarify knowledge. Monitoring of disease in companion animals may also provide a surveillance system for the safety of the food supply, as illustrated by recent outbreaks of acute renal failure and liver failure in cats and dogs in the USA caused respectively by melamine and mycotoxin contamination of pet foods.