The condition of a cat's coat is a good gauge of its overall health. Cat dandruff, characterized by a dry or oily coat with visible flakes, can be caused by anything from dry air to parasites, obesity, and serious diseases like skin cancer. Therefore, if you see these symptoms of dandruff on your cat, a trip to the vet's office may be in order.

"Many diseases show up first in the skin," says Dr. Jean Hofve, a holistic veterinarian and author of "The Complete Guide to Holistic Cat Care." "It's impossible to diagnose skin disease just by looking at it."

A veterinarian can analyze a cat's skin cells under a microscope and perform blood tests or biopsies to narrow down the cause of the dandruff.

"What we generally think of as dandruff is usually nutrition related. It is most common in overweight cats, and in cats eating mostly or only dry food," says Hofve. Therefore, says Dr. Hofve, dry kibble should be reduced or eliminated. Kibble is low in moisture and will dehydrate cats and, in turn, their skin.

"Canned, raw, and homemade foods are more likely to contain higher-quality ingredients, and therefore better quality and fresher fats," said Hofve, who also recommends looking for cat food labeled "all life stages" for higher protein and less carbohydrates.