Taurine in canine physiology and metabolic regulation

Taurine is a conditionally essential amino acid in dogs and plays a fundamental role in maintaining physiological homeostasis and metabolic health. This review systematically summarizes the biosynthesis, tissue distribution, and core physiological functions of taurine in dogs, and provides an in-depth analysis of its regulatory mechanisms across multiple organ systems, including the myocardium, retina, nervous system, reproductive system, and lipid metabolism. Particular emphasis is placed on the mechanistic links between taurine deficiency and dilated cardiomyopathy, a prevalent and clinically significant cardiac disorder in dogs. In addition, major determinants influencing taurine metabolic homeostasis are examined, with particular attention to genetic variability among breeds, differences related to body size, changes across physiological stages, and the modulatory effects of dietary composition. Accumulating evidence indicates substantial inter-individual variability in endogenous taurine synthesis capacity in dogs, which is generally insufficient to meet dynamic physiological demands under various conditions. Consequently, exogenous dietary supplementation has emerged as a critical strategy for maintaining taurine homeostasis and supporting canine health. By integrating current advances in taurine-related canine nutrition and physiology, this review provides a scientific framework for the development of precision nutritional strategies, the prevention and management of metabolic disorders, and the formulation of functional dog foods, while highlighting key knowledge gaps and future research directions in this field.