What is taurine?
Also known as 2-aminoethanesulfonic acid, taurine is an essential amino acid which was first isolated in the bile of an ox in 1827, hence the name Taurus, meaning bull. Most mammals produce taurine from other sulfur-containing amino acids, however, while cats can manufacture some taurine, it is not in adequate amounts to meet their needs. Therefore they must obtain it in their food, making it is an essential amino acid.
Why do cats need taurine?
Taurine has many biological and metabolic functions within the cat’s body including:
- Formation of bile salts which aids the digestion of fats and absorption of fat-soluble vitamins.
- It is necessary for cardiac (heart) function, brain, and nervous system function.
- Essential for the development and function of cells in the retina of the eye,
- Female reproduction and fetal growth.
- Maintains a healthy immune system.
- Helps to control blood sugar levels.
What foods contain taurine?
Meat and seafood both contain taurine. Commercially prepared cat foods have been fortified with taurine since the 1970s. Taurine deficiency occurs most often in cats who are fed dog food in their diet or homemade diets.
Taurine begins to degrade when cooked, especially in water. If you feed a home prepared diet, please speak to your veterinarian to ensure it contains adequate nutrients to meet your cat’s needs.
Taurine is found in muscle meat but is in its highest concentrations in the heart and brain.
The myocardium (heart wall) and retina contain the highest concentrations of taurine in the cat and it stands to reason that these organs are most often affected by the taurine deficiency.
While the exact mechanism taurine has on these organs is still not understood, what we do know is that a diet deficient in taurine can over time lead to feline central retinal degeneration (FCRD), eventually causing irreversible blindness, dilated cardiomyopathy (DCM) and reduced fertility in female cats.
Taurine helps to maintain a healthy immune response, deficiency can lead to a weakened immune system.
Symptoms of taurine deficiency are slow to develop. The most common symptoms of taurine deficiency include:
- Decreased vision which left untreated progress to blindness.
- Tooth decay.
- Hair loss.
Dilated cardiomyopathy may present as:
- Loss of appetite.
In the pregnant or lactating queen who is deficient in taurine the following can occur:
- Reduction in reproductive performance in females.
- Low birthrate of kittens.
- Abortions and reabsorption of unborn kittens.
- Birth defects.
- Low birth weight.
- Poor growth.
Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you. He will need to perform some diagnostic tests to determine the cause. This may include:
- Complete blood count, urinalysis, and biochemical profile to evaluate the overall health of your cat. These tests will usually not reveal any abnormalities.
- A specialised blood test to evaluate levels of taurine in the blood.
If a taurine deficiency is diagnosed, the veterinarian may recommend additional tests to check for dilated cardiomyopathy and feline central retinal degeneration.
- Ultrasound of the heart to evaluate the muscle for signs of thickening of and the ability of the heart to contract.
- Detailed eye examination to check the retina for signs of retinal degeneration and lesions on the eye.
Feed a diet with adequate levels of taurine. It may be necessary to add taurine to a homemade diet.
Caught early enough, dilated cardiomyopathy can be reversed, however, if taurine deficiency goes on for too long, heart failure can occur, which is sadly irreversible.
If feline central retinal degeneration has occurred, taurine supplementation may halt the progression of the disease, however, the damage can not be reversed.
All good quality commercial brands of cat food will contain adequate levels of taurine to meet your cat’s needs and supplementation should not be necessary.
If you decide to feed your cat a homemade diet, you will need to ensure it is nutritionally complete. There is no exact guide to how much taurine your cat should have per day. Several factors at play including:
- The age of the cat
- Type of meat
- If it is cooked or raw
- How the meat is processed (ground, in chunks, or whole)
- How much fibre is in the diet (fibre reduces absorption of taurine)
Certain processes destroy taurine:
- Freezing can also reduce taurine levels, as the meat defrosts, some water is lost, taking taurine with it
- Furthermore, mincing and grinding meat destroys taurine, so feed meat in chunks, not ground down
As has already been mentioned, cooking meat destroys taurine, so if you are planning to feed your cat a cooked homemade diet, taurine will need to be added. There is no data to suggest excess taurine is harmful to your cat, what isn’t used by the body will be excreted out via the urine. It is recommended you speak with your veterinarian before giving any supplements to your cat.
- When feeding a raw diet, include organ meats, particularly heart as this contains high levels of taurine
Taurine is water soluble, meaning that it is lost in the water. Trying to preserve levels of taurine can help with the following:
- If you do cook your cat’s meat, try to do so in as little water as possible, and place this water in the bowl with the food.
- When feeding defrosted meat, again, save the water and add to the food.