Introduction
Taurine is an essential amino acid for cats. Taurine is derived from the amino acids cysteine and methionine and is synthesized in the liver. While most mammals can produce their own taurine, cats cannot synthesize enough taurine on their own and must obtain it from their diet. Taurine is critical for cats’ health and wellbeing. It plays important roles in vision, heart function, reproduction, immune system function, and growth and development in kittens. A taurine deficiency can lead to serious health issues in cats including dilated cardiomyopathy, vision loss, and reproductive failure. Because cats are obligate carnivores, they rely on eating meat which naturally contains high levels of taurine. Cat foods should be formulated with enough supplemental taurine to prevent deficiencies.
Taurine Production in Cats
Unlike many other mammals, cats have a limited ability to produce their own taurine. Cats (as well as dogs) belong to a group of animals called obligate carnivores [1]. This means they must eat meat in their diet in order to thrive. Obligate carnivores lack sufficient levels of an enzyme called cysteine sulfinic acid decarboxylase (CSAD), which is needed to produce taurine from other amino acids [2].
While some mammals like rodents and primates can produce their own taurine easily, cats cannot. Their limited CSAD production means cats cannot reliably produce enough taurine on their own to meet their bodily needs. This makes obtaining dietary taurine critical for cats.
Taurine’s Role in Vision
Taurine is critical for eye health and normal vision in cats. Cats cannot synthesize enough taurine on their own and must obtain it from their diet. Taurine helps maintain the correct structure and function of the retina in a cat’s eye.
The retina contains photoreceptor cells that detect light and convert it into signals that are transmitted to the brain, allowing cats to see. Taurine helps form and preserve these photoreceptor cells. It also supports the function of the retinal ganglion cells that carry visual signals from the retina to the brain through the optic nerve.
Without adequate taurine, cats can develop severe retinal degeneration, loss of vision, and blindness. Taurine deficiency causes the retina to slowly atrophy, damaging the photoreceptor cells. Retinal detachment may also occur. These retinal abnormalities are irreversible once vision loss sets in.
Multiple studies have proven the essential role of dietary taurine in preventing vision loss and maintaining normal feline vision [1]. Taurine deficiency is one of the most common nutritional causes of blindness in cats. Ensuring cats consume enough taurine is critical for preserving their eyesight.
Taurine’s Role in Heart Health
Taurine plays a critical role in supporting cardiovascular health in cats. Studies have shown that cats fed a taurine-deficient diet developed a condition called dilated cardiomyopathy (DCM), which is a form of heart disease characterized by enlargement and weakening of the heart muscle (1). DCM can lead to congestive heart failure if left untreated.
One notable study showed that 21 out of 36 cats (58%) with DCM showed significant improvement after being supplemented with taurine (2). The researchers concluded that taurine deficiency was a major factor in feline DCM and that supplementation could reverse the condition in many cases.
It’s believed that taurine helps maintain the structural integrity of the heart muscle cells. When taurine levels drop, the heart muscle cells weaken and stretch, impairing the heart’s ability to pump blood effectively (3). Taurine may also have antioxidant effects that protect the heart against damage from oxidative stress.
Overall, studies clearly demonstrate that adequate taurine intake is essential for preventing DCM and ensuring the long-term health of a cat’s cardiovascular system.
(1) https://vcahospitals.com/know-your-pet/taurine-in-cats
(2) https://pubmed.ncbi.nlm.nih.gov/1500324/
(3) https://www.petmd.com/cat/conditions/cardiovascular/taurine-deficiency-cats
Taurine and Reproduction
Female cats have a high requirement for taurine during pregnancy and lactation to support proper development of their kittens. Taurine deficiency during pregnancy can lead to reproductive failure and poor growth of kittens (Sturman, 1991).
Specifically, taurine deficiency causes mortality and resorption of embryos, death of fetuses in utero, stillbirths, low birth weight and growth retardation of kittens after birth (Sturman, 1986). The reproductive performance of taurine-deficient female cats is very poor.
During pregnancy and fetal development, taurine promotes proper formation of the eyes and central nervous system in kittens (https://vcahospitals.com/know-your-pet/taurine-in-cats). It ensures normal retinal structure, function of rod cells, and visual acuity.
Taurine also supports proper heart and muscle development in the fetuses. It helps prevent dilated cardiomyopathy and other cardiovascular abnormalities that can be fatal for newborn kittens if their mother was taurine deficient.
By contrast, female cats receiving adequate dietary taurine have normal pregnancies, deliveries and litter development. Ensuring pregnant and nursing cats get enough taurine is crucial for kitten health and survival.
Taurine’s Effect on Growth
Taurine plays a critical role in healthy development and growth in kittens. Kittens that are deficient in taurine can experience delayed growth and development.
According to a study published in the Journal of Nutrition by Sturman et. al https://pubmed.ncbi.nlm.nih.gov/1941217/, a diet low in taurine resulted in modest taurine depletion in pregnant cats. Kittens born to these deficient mothers showed compromised reproductive performance. The kittens exhibited low birth weights and reduced growth rates compared to kittens born to mothers with normal taurine levels.
Taurine deficiency affects proper development by impairing vision and causing poor retinal function in kittens. It also leads to dilated cardiomyopathy, which can further hinder growth.
Ensuring pregnant and nursing cats receive adequate amounts of taurine, either through diet or supplementation, is critical for normal kitten development and growth.
Obtaining Taurine
Cats obtain taurine primarily through their diet. In the wild, cats get taurine by eating meat. Taurine is found abundantly in animal-based proteins like chicken, turkey, and fish (VCA Animal Hospitals). When cats eat whole prey animals, they consume the muscles which contain high levels of taurine. Commercial cat foods are fortified with added taurine to meet cats’ nutritional needs.
Taurine is an essential amino acid for cats, meaning their bodies cannot produce enough on their own and it must come from food. Cats who do not get enough taurine in their diet are at risk for developing a number of health issues. Taurine deficiency can cause vision loss, heart problems, reproductive issues, and impaired growth and development in kittens. Ensuring cats’ food has adequate levels of taurine is critical for their health.
Symptoms of Deficiency
Cats with low taurine levels can develop several concerning symptoms over time. Some of the most common symptoms of taurine deficiency include:
- Retinal degeneration, which can lead to blindness (https://vcahospitals.com/know-your-pet/taurine-in-cats)
- Heart problems like dilated cardiomyopathy, where the heart becomes enlarged and cannot pump blood effectively (https://www.petmd.com/cat/conditions/cardiovascular/taurine-deficiency-cats)
- Reproductive issues such as stillborn kittens or low birth weight (https://wagwalking.com/cat/condition/taurine-deficiency)
- Poor growth in kittens
- Loss of appetite
- Lethargy and fatigue
- Unkempt appearance in cats who stop grooming
These symptoms tend to worsen over time if taurine deficiency is left untreated. Cats rely completely on their dietary intake to obtain this essential amino acid, so deficiencies can develop gradually as stores become depleted. That’s why routine screening and prevention through proper nutrition is so important for feline health.
Diagnosing Deficiency
Veterinarians can diagnose taurine deficiency in cats by testing blood and urine samples. Blood testing is the most common method, as blood taurine levels directly correlate with body stores of this amino acid. Normal blood taurine concentrations in cats range from 40-120 nmol/mL. Levels below this indicate deficiency. Urine testing can also be done to measure taurine excretion, with low levels pointing to inadequate body stores. However, blood testing is more accurate.
In addition to direct taurine testing, vets may run a complete blood count and serum biochemical profile. These can show abnormalities like anemia, heart muscle damage, and liver disease that result from taurine deficiency. An echocardiogram may also be recommended to check for heart problems. Diet analysis can help determine if inadequate taurine in the food is the cause.
According to the Amino Acid Laboratory at UC Davis Veterinary Medicine, taurine blood test results are usually available within 10 working days. This allows vets to definitively diagnose taurine deficiency and quickly start cats on supplementation.
Treating Taurine Deficiency
If a cat is diagnosed with clinically low levels of taurine, the main treatment is taurine supplementation. This is typically done by adding taurine to the cat’s food or giving taurine capsules/tablets directly. According to the VCA, supplementation can reverse the effects of taurine deficiency if caught early enough. However, in some cases, especially with dilated cardiomyopathy, the heart damage may be irreversible even with supplementation.
The dosage and length of taurine supplementation varies depending on factors like the cat’s age, weight, and severity of deficiency. Kittens and pregnant/lactating cats may need higher doses. In mild cases, supplementation for just a few weeks may restore normal taurine levels. But cats with dilated cardiomyopathy often require lifelong daily supplementation to control the disease [1].
Besides oral supplementation, there are also taurine-rich cat foods formulated for heart health. Switching to one of these therapeutic diets, in addition to supplementation, can help manage taurine deficiency. It’s important for owners to work closely with their veterinarian to determine the optimal supplemental and dietary regimen for an individual cat based on regular monitoring and blood taurine measurements [2].
