A frequent error is feeding dog food. Never feed dog food to a cat! Cats require twice as much protein and B vitamins as do dogs. Cats, unlike dogs, cannot convert certain dietary precursors into necessary amino acids and water soluble vitamins. A cat given dog food over a long period can develop taurine deficiency, vitamin A deficiency (night blindness), niacin deficiency, retinal degeneration, and other serious or fatal illnesses.
Another common error is to overdose a cat with vitamins A and D or calcium and phosphorus, either by giving the vitamins directly or by supplementing the diet with products that are high in them (such as raw liver or fish oils). Excess vitamin A causes sterility and loss of hair. Excess calcium, phosphorus, and vitamin D cause metabolic bone and kidney disease.
Raw fish should not be fed to cats. Raw fish contains an enzyme that destroys vitamin B1 (thiamin). A deficiency of this vitamin results in brain damage. Fish is also deficient in vitamin E and has the potential to transmit diseases.
Never feed dog food. It is deficient in essential nutrients cats require.
Specialty foods and even table scraps can be given as treats once or twice a week-but only after the regular diet is eaten. Cooked meats (including organ meats such as liver or kidney), cottage cheese, cooked vegetables, cooked fish, milk, and yogurt are foods with strong taste appeal that cats seem to enjoy. Only give them in small amounts and do not offer dairy products if your cat appears to be lactose intolerant (usually evidenced by diarrhea).
Never feed meats exclusively.
Treats should never exceed 20 percent of a cat’s total daily food.
Uncooked meat and raw fish should not be given because of the dangers of vitamin deficiency and transmitting diseases.
Vitamin and mineral supplements are not necessary or desirable if you are feeding a balanced cat food.
Cats have highly selective eating habits. The location of the food dish, noise, the presence of other animals, and other threats or distractions can adversely affect how much they are willing to eat. A cat in a boarding facility may go an entire week without eating (which can be dangerous).
Cats prefer to have their food served at room temperature.
Many cats will not eat if the food dish is located near the litter box.
Water is a very important nutrient for cats. Always have plenty of fresh water available. Canned food diets are more likely to provide an adequate amount of water than are other types of food.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"