Taurine is an amino acid – one of the building blocks of proteins within the body. Cats cannot make sufficient amounts of taurine on their own and so must eat food that contains relatively large amounts of the substance, or they will get sick as a result of taurine deficiency. Dogs are able to manufacture more of their own taurine and so generally are more tolerant of low levels of the amino acid in their diets. Problems associated with taurine deficiency have become much less common now that pet food manufacturers recognize the amino acid's importance and provide suitable levels in their diets.
Cats suffering from a taurine deficiency can develop poor eyesight and become blind because of deterioration of their retinas. A specific type of heart disease called dilated cardiomyopathy is also likely when a cat does not eat enough taurine. These animals may become less active, have unusually rapid or deep breathing, cough, or die suddenly. Some canine cases of dilated cardiomyopathy are also caused by taurine deficiency, as a result of either an atypical diet or the unusually high needs of specific breeds (e.g., Cocker spaniels and Newfoundlands). A veterinarian can determine whether a taurine deficiency is responsible for a pet's disease by sending a blood sample to the laboratory for measurement of the amino acid's concentration.
Some cases of taurine-related dilated cardiomyopathy will resolve when the amino acid is added to the pet's diet. In other instances, however, irreversible damage has occurred, and heart function will never be normal. A cat's vision may also improve with taurine supplementation, but animals with longstanding blindness are unlikely to regain their sight.
Written by: Jennifer Coates, DVM
Last reviewed: October 2, 2008