Cats can’t skip more than a few meals without getting very ill. Why is this?
Cats are obligate carnivores. Unlike dogs and humans, who are omnivores that use carbohydrates/sugars for energy, a cat’s body uses protein as the main source of energy. This explains why cat food has a high percentage of protein, usually over 35%, ideally 40% or more. Without that daily source of high protein, a cat will break down muscle mass to get protein.
Many housecats have little muscling to begin with. In other words, not much to spare to use when needed. In obese and muscle-wasted cats, a shorter time of fasting will cause fat (not carbohydrates) to be used for the body’s needs. Once this happens, a disease called hepatic lipidosis or “fatty liver” manifests. This is basically a cat’s metabolic response to starvation. Jaundice, yellowing of the skin, may occur as well as vomiting and lethargy.
Once the path for processing fat into energy is used, it becomes difficult to switch back to the normal path of using protein. Even if your cat starts eating again, a recovery time is needed and several days of hospitalization is often required. For some cats, the problem is fatal.
Finding out immediately why your cat is not eating and fixing the problem is essential to preventing “fatty liver” disease. Call your local veterinarian to have your cat seen right away if 24 hours has passed and your cat has not eaten. If more than two days of decreased appetite is noticed, have your pet checked as well. It is sometimes difficult to tell when a cat fed free choice stops eating. Portion-measured meal feeding is recommended.