Taurine in Cat and Dog Diets

Taurine (2-aminoethanesulfonic acid) is a colorless crystalline substance obtained from the bile of mammals. This unusual amino acid may function as neurotransmitter and plays an important tole in early brain maturation. It is now considered an indispensible amino acid for felines. The fundamental importance of taurine in the maintenance of retinal function and brain development in cats led to the inclusion of taurine as a supplement in most commercial cat food.1

Food Sources of Taurine

Although taurine is the end product of sulfur amino acid metabolism, it is usually obtained from the diet as well. Taurine is present in most animal foods and either absent or present in very low levels in most plant foods. Relatively high concentrations of taurine have been reported in seaweeds.2

Taurine Deficiency in Cats

Signs of Taurine Deficiency in Cats

Although taurine is plentiful in most mammalian tissues as a free amino acid, the cat's synthesis of taurine is insufficient to meet its biological needs. Taurine deficiency in cats results in feline central retinal degeneration (FCRD) and blindness; feline dilated cardiomyopathy (DCM) and heart failure; immune system problems; abnormal hind legs development; poor newborn kitten growth; deafness; abortions and low survival of the kittens; congenital defects including hydrocephalus and underdeveloped brain. Signs of heart failure such as dehydration, lethargy and low body temperature are often overlooked by cat owners before an apparent sudden developement of difficulty breathing.3

With the discovery of the taurine deficiency as a cause of DCM, cat foods were altered to provide greater levels of taurine. Because of this, it is rare to see taurine deficiency DCM in clinical practice today.



Taurine and Dilated Cardiomyopathy in Dogs

Although taurine is not dietarily essential for dogs, recently reported experimental and clinical observations in dogs are supportive of the possibility that consumption of diets with inadequate and/or unavailable taurine, or taurine precursors, can result in taurine deficiency and low blood taurine concentrations. This can lead to the development of abnormal cardiac function and DCM.

Some newer more promising therapies for dogs with dilated cardiomyopathy (DCM) are taurine and carnitine. Deficiencies of these nutrients have been shown to cause DCM in dogs, and some breeds of dogs have shown dramatic improvement in myocardial function after supplementation with one or both nutrients. Although most dogs diagnosed with DCM do not have a documented taurine or carnitine deficiency, they may still be benefit from supplementation. These nutrients are safe to administer to dogs. For some owners, the high cost of carnitine is the only deterrent to giving their dogs supplements of both nutrients.5

References

  1. Cellular and molecular biology of nitric oxide. Jeffrey D. Laskin, Debra L. Laskin
  2. Modern nutrition in health and disease. Maurice Edward Shils, Moshe Shike
  3. Nutrient requirements of dogs and cats By National Research Council (U.S.). Ad Hoc Committee on Dog and Cat Nutrition
  4. Kirk-Othmer Food and Feed Technology. Wiley
  5. Taurine and carnitine in canine cardiomyopathy. Sanderson SL. In: Vet Clin North Am Small Anim Pract. 2006 Nov;36(6):1325-43