Cats are “obligate carnivores” meaning that their metabolism needs animal-based proteins in order for them to survive. This is due to cats having evolved as a predator species and their need for protein as their main energy source. Therefore, they are not able to survive on a plant-based diet as omnivorous species such as humans and dogs are.
Amino acids are the main component of proteins. Some amino acids can be synthesised (created) in the body by metabolising other amino acids. Some amino acids cannot be synthesised, or the amounts synthesised are not sufficient to meet the body’s demand. These are called “essential amino acids” because they need to be provided in the diet.
In cats, the most commonly-recognised essential amino acid is taurine, which is only found in animal-derived protein. Cats can’t synthesise enough taurine, plus it isn’t easily absorbed if the carbohydrate content of the diet is too high. Taurine isn’t easily stored in the cat’s body and it is easily lost, so ongoing intake of taurine is necessary to prevent deficiency. Most commercial cat diets, particularly the premium diets, are supplemented with taurine and further supplementation is not necessary.
Signs of taurine deficiency can take several months to develop (less time in growing kittens) and can result in:
- retinopathy (damage to the retina at the back of the eye, causing blindness)
- cardiomyopathy (damage to the heart muscle)
- changes to white blood cells (which are involved in immunity and fighting infection)
- abnormal growth and development in kittens
Taurine deficiency causes a reduction in quality of life and reduced lifespan (DEATH) if left untreated.
If your personal values mean that you eat a vegetarian or vegan diet yourself, and you want these values to carry over to what your pets eat, you might want to consider a non-carnivore pet, such as a dog, rabbit or guinea pig. Cats can absolutely not survive for long without an animal-based diet.