Besides protein, a healthy cat needs various nutrients, including fats, water, milk, vitamin A, vitamin D, calcium, and phosphorus.
Cats also require high levels of fats in their diet. This is also used as a source of energy as well as a source of essential fatty acids and vitamins. Diets containing high levels of carbohydrates do not seem to be very palatable to cats and they may not contain sufficient quantities of proteins and fats.
The water requirement of cats varies considerably with the type of diet being fed. Cats fed on canned foods, which contain as much as 75 percent water, only need to drink small quantities once daily. If dry food is the main source of food a much greater quantity of water must be provided as these foods only contain about 10 percent water.
The presence of lactose in the diet from milk or milk derivatives gives some cats and kittens diarrhea. This may be caused by the lack of the enzyme which is essential in the digestion of lactose. Many commercial cat foods contain dried milk powder and this may be the reason that some cats tolerate one type of prepared food better than another.
4. Vitamin A
Cats require comparatively high levels of Vitamin A. Pregnancy and the subsequent feeding of a litter increase the requirement dramatically. Lack of sufficient levels of Vitamin A may be reflected in a weak litter failing to gain weight and susceptible to disease.
Vitamin A is contained in the liver, eggs, and milk. Care should be taken not to overdo the amounts of Vitamin A given, as an excess of this vitamin can bring about deformities of the skeleton. Care should be taken to feed the liver only once or twice weekly in small amounts.
5. Vitamin D
Vitamin D is required only in very small quantities and the use of Vitamin supplements intended for human use should be used with caution as these usually contain high levels of Vitamin D.
6. Calcium and phosphorus
The important minerals in the diet of cats are calcium and phosphorus. In the newborn kitten, calcium levels are very low and the only source is the milk of the mother. Cat’s milk contains relatively low levels of calcium, so by the time the kitten is weaned at 6 weeks, it is growing rapidly but still has no reserves of calcium. It is most important that the owner realizes this and adjusts the diet accordingly.