Both fat and water soluble vitamins are important nutrients for dogs and cats. Excesses or deficiencies can lead to a serious nutritional imbalance.
Vitamins serve many essential functions for both dogs and cats and play an important role in both canine and feline nutrition.
What are Vitamins?
Vitamins are organic molecules that are not carbohydrates, proteins or fats. They are essential canine and feline nutrients and are necessary in very small amounts in the diet of all dogs and cats. Although there are a few exceptions, in most instances vitamins cannot be synthesized by the body in the quantities that are needed to allow the body to function normally. If vitamins are not present in sufficient quantities, nutritional deficiencies can result, leading to health problems and illness. It is also possible to over-supplement and produce illness.
What Functions do Vitamins Play in Canine and Feline Nutrition?
Vitamins are responsible for many functions. These functions include:
- aiding in the release of energy from other nutrients
- acting as free radical scavengers
- serving as co-enzymes or enzyme precursors in various metabolic processes
- helping to preserve cell membrane integrity
- aiding in blood clotting
- aiding in the transmission of nerve impulses
Vitamins as Dog and Cat Nutrients
Vitamins are classified as fat soluble or water soluble.
The fat soluble vitamins are digested and absorbed with the fat in the diet and can be stored in large quantities in the body. There are four fat-soluble vitamins:
- Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
Water soluble vitamins are not stored in significant quantities and need to supplied in the diet daily. These vitamins require only water to be absorbed from the intestinal tract. Ten water soluble vitamins exist:
- Vitamin C (ascorbic acid)
- thiamine (Vitamin B1)
- riboflavin (Vitamin B2)
- niacin (Vitamin B3)
- pantothenic acid (Vitamin B5)
- pyrodoxine (Vitamin B6)
- cobalamin (Vitamin B12)
- folic acid
Vitamin A in Canine and Feline Nutrition
Vitamin A can be manufactured by the canine body by converting beta-carotene (which is present in many plants). However, in cats, Vitamin A is required pre-formed in the diet since cats cannot convert the beta-carotene to vitamin A.
Vitamin A is responsible in part for normal vision, normal bone growth and tooth development, and maintaining normal epithelial layers (outside layers) of multiple organ systems. It also plays a role in reproduction.
Deficiencies of vitamin A result in eye problems (retinal degeneration), poor hair coat, abnormal bone development and impaired ability to reproduce. Excesses result in skeletal deformities, bone fractures, bleeding in the intestinal tract and slow growth.
Vitamin D as a Nutrient for Dogs and Cats
Vitamin D plays an important role in absorbing calcium and phosphorus and helps with normal mineralization of bones. It is also involved in the production of insulin and in supporting normal immunity.
A deficiency in vitamin D results in rickets in puppies and kittens and osteomalacia in adult dogs and cats. Both conditions result from abnormal bone mineralization.
Excesses of vitamin D supplementation result in hypervitaminosis D and hypercalcemia.
Vitamin E in the Canine and Feline Diet
Vitamin E functions as an anti-oxidant in the diet and protects the body from damage from free radicals. Vitamin E excesses and/or deficiencies are rarely reported and it is considered to be a reasonably non-toxic vitamin.
Vitamin K in Pet Nutrition
The primary function of vitamin K is playing a role in the ability of the blood to clot properly. Deficiencies in vitamin K can lead to abnormal bleeding and can be life-threatening. Very few reports of vitamin K toxicity have been recorded.
Water Soluble Vitamins in Canine and Feline Nutrition
Vitamin C (ascorbic acid) is not considered to be an essential vitamin in the diet of dogs and cats because healthy dogs and cats are able to metabolize glucose to produce ascorbic acid. Deficiencies have not been reported in dogs and cats, though in humans deficiencies can cause scurvy.
The B-complex vitamins make up the remainder of the water soluble vitamins. Thiamine, riboflavin, niacin, pyrodoxine, pantothenic acid and biotin all function as co-enzymes in the production of energy. (Co-enzymes are small organic molecules that must be present to work with an enzyme in order to make a specific reaction occur.)
Folic acid, cobalamin and choline are partially responsible for normal growth, maintenance of tissues and for production of blood cells.
Deficiencies of water soluble vitamins are rare in healthy animals.
- Though uncommon, deficiencies in thiamine can cause abnormalities in the central nervous system.
- Cats need niacin present in their food, unlike dogs which can synthesize niacin from tryptophan.
- Raw egg whites contain avidin, which can render biotin unavailable. Caution should be used when feeding raw eggs, particularly egg whites, to pets.
- Diseases which cause abnormal growth of pathogenic bacteria in the intestinal tract can result in increased need for some B vitamins, such as folic acid and biotin. The same is true of antibiotic administration.
Vitamins play an important role in both canine and feline nutrition. They are nutrients that have many essential functions for dogs and cats.