Reviewed and updated for accuracy on April 15, 2020 by Amanda Ardente, DVM

Amino acids are the basic building blocks of protein. There are 22 amino acids that are needed for proper functioning of the body.

In dogs, 12 of these amino acids are “nonessential,” meaning the body can make them on its own. The other 10 amino acids are “essential,” meaning they must be supplied by the diet.

Taurine is known to be a dietary requirement for cats and may be for some dog breeds as well.

Here’s what you need to know about the amount of taurine in dog food, the risk of dilated cardiomyopathy (DCM) from taurine deficiency, and whether you should consider taurine supplements for dogs.

Does Dog Food Have Taurine?

Since taurine is known to be ‘essential’ for cats, cat food must have taurine supplemented in quantities established by the American Association of Feed Control Officials (AAFCO) and the National Research Council (NRC).

To date, however, there are no stated requirements for supplementing dog food with taurine. The extent to which dogs may require dietary taurine is still under investigation and may be breed dependent.

Taurine Deficiency and Dilated Cardiomyopathy in Dogs

Taurine deficiency is one cause of a heart condition called dilated cardiomyopathy (DCM), where the heart muscle thins and the chambers become enlarged. This is true for cats, and may now also be true for dogs.

Recently, studies have found a connection between DCM and these breeds of dogs:

While research is ongoing, there are theories that the onset of DCM is related to the diet, specifically, grain-free diets. However, the question remains whether the DCM occurs due to an overall lack of taurine in the dog food or other dietary factors that cause problems with taurine digestion, absorption, metabolism, and/or excretion.

How Do Vets Test for Taurine Deficiency?

Veterinarians would first need a thorough history of your dog's health, including a list of symptoms and the diet fed.

Then, your veterinarian would conduct a complete physical examination of your dog and do routine blood work, including:

Complete blood count (CBC)

Biochemical profile (chemistry panel)

Urinalysis

Blood concentrations of taurine can be measured by a laboratory to determine whether deficiency is likely. There are “normal” ranges for blood-taurine concentrations in dogs, so if the measured concentration is lower than that range, taurine deficiency is probable.

What Health Issues Are Caused by Taurine Deficiency in Dogs?

Taurine is distributed throughout the body with high concentration in certain tissues, including the heart, the retina of the eye, and the brain. Taurine deficiency may be suspected if heart disease, retinal disease, and/or cystinuria are identified via the physical exam and/or initial laboratory results.

Taurine Deficiency and Heart Disease

If heart disease is suspected based on physical exam and/or blood work (e.g., low blood taurine), then chest X-rays, electrocardiogram (ECG), and other diagnostic measures would be recommended in order to evaluate and diagnose the severity of the disease.

Taurine Deficiency and Eye Problems

Likewise, blood-taurine concentrations should be evaluated if retinal damage (problems with your dog’s eyes) is found during a physical exam by your veterinarian.

Taurine Deficiency and Urinary Issues

If cysteine stones/crystals are found in the urinalysis, it is likely your dog has an issue metabolizing amino acids.

Cystinuria is more common in certain breeds, such as the following:

However, if present in any dog, it may indicate amino acid malabsorption, which can potentially be causing taurine deficiency.

Taurine Supplements for Dogs

Taurine supplementation is the treatment of choice for dogs suffering from taurine deficiency. The length of time that your dog will need taurine supplementation will depend on the severity of the deficiency and your dog's ability to maintain levels of taurine as it is ingested.

In some dogs, lifetime taurine supplementation may be required to prevent recurrent taurine deficiency. For other dogs, a diet change may be needed in addition to taurine supplementation, and if symptoms resolve, supplementation may be discontinued.

Managing Taurine Deficiency

Good nursing care is required at home during treatment of taurine deficiency.

Give all medications and supplements at the prescribed or recommended dose and frequency to avoid aggravation of the symptoms.

In the case of heart disease, your dog will need proper rest in a stress-free environment at home.

Your veterinarian will schedule follow-up examinations to monitor the treatment response in your dog. While dramatic improvement is seen in most animals, some animals may not respond completely to taurine supplementation and need further treatment.

Featured Image: iStock.com/Moyo Studio

retina The layer of the eye that is charged with receiving and processing images

urinalysis An in-depth examination of the properties of urine; used to determine the presence or absence of illness

metabolism The group of processes that involve the use of nutrients by the body

excretion Eliminating or the material that has actually been eliminated

electrocardiogram A record of the activity of the myocardium

amino acids Organic substances that aid in the creation of proteins; also the end product of the decomposition of certain proteins.