Feline requirements for most of the essential amino acids are similar to those for other species with the exception of some essential amino acids such as arginine and taurine.
Cats require more arginine than most other animals do, however, because they lack an intestinal enzyme, pyrroline-5-carboxylate synthase, required for synthesis of the arginine precursor, ornithine (a urea cycle pathway intermediate). Arginine is required for normal protein synthesis and ammonia detoxification.
Arginine enables conversion of ammonia to urea.
Cats can develop severe hyperammonemia from anorexia or ingestion of an arginine-free meal. Arginine has other important roles that include increasing endocrine secretagogue activity, improving nitrogen retention, acting as a substrate for nitric oxide production, reducing nitrogen loss in postoperative patients, enhancing collagen deposition in wounds, enhancing T-cell function, and the growth of lymphocytes.
Protein sources commonly used in the formulation of cat food will easily fulfill all the arginine requirements. Lipid accumulation observed in cats suffering from hepatic lipidosis does not appear linked to arginine deficiency or orotic acid accumulation as has been described in rats.