Taurine for Cats: Why This Amino Acid Is Essential
Many amino acids matter in nutrition, but taurine holds a special place in the story of cats. Early in the history of pet food, cats fed certain diets went blind and developed heart failure. Researchers traced the problem to a lack of taurine, and the discovery changed pet food forever.
What is taurine?
Taurine is a sulfur-containing amino acid, found naturally in animal tissues, especially muscle, heart and organs. Strictly speaking, it is not used to build proteins. It plays many roles in the body.
Why cats cannot make enough
Most mammals can produce taurine from other amino acids. Cats do so very inefficiently, because their bodies have low levels of the enzymes involved. Cats also use taurine to form bile salts, so they lose it continuously. As a result, taurine is an essential nutrient for cats, and they must get it from food. This is part of what makes them obligate carnivores. See how to read a cat food label.
What taurine does
- Heart. Helps the heart muscle contract properly.
- Eyes. Needed for the retina, the light-sensing layer at the back of the eye.
- Digestion. Taurine is used to make bile salts, which help absorb fat.
- Reproduction and development. Needed for fetal development and kitten growth. See kitten growth and development week by week.
- Immune system and nervous system. Supports normal function.
Signs of taurine deficiency
Deficiency develops over months. Signs may include:
- Dilated cardiomyopathy. A weakened, enlarged heart that cannot pump well, causing breathing difficulty, lethargy and collapse
- Retinal degeneration, with gradual vision loss and eventually blindness
- Poor growth and reproductive failure
- Hair loss or a dull coat
- Digestive problems and weight loss
Heart disease from taurine deficiency has become rare since manufacturers began adding taurine, and it is different from hypertrophic cardiomyopathy, the most common feline heart disease, which is mostly inherited. See hypertrophic cardiomyopathy in cats. If caught early, deficiency-related heart disease can often be reversed with taurine supplementation. Any breathing difficulty is an emergency. See the emergency warning signs guide.
Where cats get taurine
Taurine is found in meat, fish, shellfish and organ meats. Dark poultry meat and heart are rich sources. Plant foods contain none. Commercial foods labeled complete and balanced contain added taurine at levels that meet nutritional standards, and wet foods are generally formulated with higher levels, because processing can reduce availability.
Diets that risk low taurine
- Vegetarian and vegan diets. Cats cannot be healthy on a plant-only diet.
- Poorly formulated homemade diets. Cooking and grinding can reduce taurine, so recipes need professional balancing.
- Raw diets that are not balanced. See raw food diets for cats.
- Dog food fed to cats. Dog food is not formulated for cats. See can cats eat dog food.
- Unbalanced boutique diets. Always check for a statement of nutritional adequacy.
Should you add taurine?
If your cat eats a complete and balanced commercial food, extra taurine is not needed. Do not supplement without veterinary advice, though taurine is generally considered safe. If you feed homemade food, work with a board-certified veterinary nutritionist. See are vitamins and supplements necessary for cats.
Choosing a food
Look for a nutritional adequacy statement on the label, stating the food is complete and balanced for your cat's life stage. See wet vs dry cat food and is grain-free cat food better.
Kittens and pregnant cats
Kittens and pregnant or nursing queens have high needs and should eat foods designed for growth and reproduction. See kitten feeding schedule.
Taurine in different foods
Wet foods tend to contain more taurine than dry foods per serving, since taurine is lost during the high heat of extrusion and dry foods are supplemented to compensate. A complete and balanced food of either type meets the standard. If you feed a mix, make sure each meets that standard.
History of the discovery
In the 1970s and 1980s, scientists found that cats fed diets low in taurine developed blindness and heart failure. Pet food companies began adding taurine, and the incidence of the disease dropped dramatically. It remains a powerful example of why cat food must be formulated for cats.
Questions to ask about your cat's food
Ask the manufacturer or your vet whether the food meets the nutritional standard for your cat's life stage, whether it was tested in feeding trials, and who formulates it. A reputable company will answer clearly. If your cat has had unexplained weight loss, vision change or breathing trouble, ask whether diet could be a factor and whether blood taurine testing makes sense.
When to see a vet
If your cat has breathing trouble, vision changes or poor growth, see a vet. Use the US vet directory to find a clinic, and see cat vet visit costs.
Frequently asked questions
Do cats need taurine supplements?
Not if they eat a complete and balanced commercial cat food. Ask your vet before supplementing.
Where does taurine come from?
Meat, fish and organs, especially heart and dark meat.
Can cats be vegetarian?
No. Cats are obligate carnivores and need nutrients found in animal tissue.
Does cooking destroy taurine?
Some is lost, which is why commercial foods add extra.
Sources and further reading
Pet food rules and nutrient standards come from regulators and professional bodies. Start here when you want the primary source.
- AAFCO: pet foodThe body behind U.S. pet food nutrient profiles and labeling standards.
- FDA Center for Veterinary MedicineU.S. regulator for animal food, drugs and recalls.
- ASPCA: people foods to avoid feeding your petsWhich common kitchen foods are unsafe for dogs and cats.
Tailwisp is independent and written under our editorial policy. Learn who we are, or browse all cat guides.
This article is general educational information, not veterinary advice. Every cat is different. If your cat is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.