Why do cats need taurine?

Taurine is an amino acid cats can’t make enough of on their own, so they have to get it from their diet, and it comes only from animal tissue. It’s vital for heart muscle, vision and reproduction, and a long-term deficiency can cause a serious heart condition and blindness. This is a big reason cats are obligate carnivores and can’t thrive on a vegetarian diet or on dog food. Any complete-and-balanced cat food with an AAFCO statement already includes enough taurine, so you don’t need to supplement a properly fed cat.