79 Functional Amino Acids in Dogs and Cats: Implications for Overall Health

Abstract

Abstract The majority of pets depend exclusively on commercial pet food supplied by their owners, who now more than ever are looking for diets supporting the health and well-being of their companion animals. Due to the diverse roles of amino acids beyond protein synthesis, their use as functional nutrients in canine and feline nutrition has gained attention. Dietary supplementation of tryptophan or tyrosine, as the precursors of serotonin and catecholamines, respectively, may reduce stress, anxiety-related and agonistic behavior in dogs. Surplus dietary arginine may also confer benefits by improving cognitive function in aging dogs likely through the enhancement of nitric oxide synthesis. In adult cats, phenylalanine has been studied for its potential effect on delaying gastric emptying and promoting satiety, which could aid in prevention of feline obesity. On the other hand, diets with greater dietary lysine:calorie may protect lean body mass of senior cats, and thus, may help combat sarcopenia. Studies investigating the functional role of amino acids in dogs and cats, however, are limited and the results are often conflicting. Additionally, data on empirical determination of amino acid requirements in adult dogs and cats are scarce, potentially preventing the dietary delivery of the ideal ratios of amino acids and subsequently the provision of specific amino acids in targeted doses above the requirement to evaluate their potential functional roles. Consequently, although the functional properties of some amino acids in dogs and cats are promising, more research focusing not only on their potential health benefits, but also on the empirical determination of amino acid requirements in dogs and cats is warranted to promote their use as functional nutrients in pet food.