Nutrition, Skin, and Cats

My cat’s haircoat is a problem. He sheds all the time and sometimes gets sores where he has chewed himself. My veterinarian says he may have allergies and that he may need to eat a special diet. I’m not sure I understand how what he eats can make a difference in his skin and haircoat.

As far back as 1953, veterinarians recognized the relationship between nutrition and the health of the skin and haircoat. In a veterinary dermatology textbook from that era, we find the following quote:

“Dermatoses (skin diseases) affecting various species of animals are more commonly associated with malnutrition than they are with… a good state of nutrition.”

Approximately 25% of cat visits to the veterinarian involve problems with the skin and haircoat. The most common skin problems in cats are:

1. Abscesses
2. Allergies (e.g. flea bite allergy)
3. Immune-system mediated skin ulcers/plaques
4. Parasites
5. Fungal infections
6. Food hypersensitivity/intolerance
7. Self-trauma
8. Skin cancers

Even in cats not experiencing an adverse reaction to food, the skin and haircoat can be affected by many nutritional factors.

One major way that nutrition can affect a cat’s skin and haircoat is when there is a nutritional deficiency of some kind. This often happens when a cat is fed a homemade diet over a long period of time. A nutritional deficiency can also occur when cats are fed a poor quality commercial dry food, a commercial food that contains nutrient excesses, or if a commercial diet is supplemented inappropriately.

A cat’s age is important when considering a potential nutritional problem with skin and haircoat quality. A cat’s body requires higher levels of certain nutrients during growth than during adulthood. Because the body has only so many ways to respond to diseases or nutritional deficiencies, it is important to look for and address any systemic diseases or parasites that may be at work. Nutritional issues should be considered if any of the following changes in the skin and haircoat emerge:

• Sparse, dry, dull hair with “split ends”
• Slow growth or no growth of hair from spots that have been clipped or shaved
• Accumulation of dry skin scales
• Pressure sores
• Change in/loss of hair color

Food-related risk factors for nutrition-related skin disease include:

• Lower fat content
• Poor quality protein or fat
• Lower nutrient digestibility
• High levels of some nutrients that can inhibit absorption of zinc (critical for normal skin)

Protein and energy are needed for skin and haircoat development. If food does not have adequate protein or fat, then the cat may develop areas of hair loss, or the hair may lose color. The haircoat may become dry, dull, and brittle. For adult cats, the protein level should be 30–45% on a dry matter (DM) basis, and fat should be 10–15% DM. For kittens, the protein should be 35–50% DM, and fat should be 20–35% DM. Overall digestibility should exceed 80%.

Another critical group of nutrients for good canine skin and haircoat quality are the essential fatty acids (EFAs). EFAs must be provided in the diet because the body cannot manufacture them. EFA deficiency causes the skin to become scaly and dry, the hair mats easily, and the skin loses its elasticity. Fortunately, EFA deficiencies are easily remedied by ensuring appropriate levels in the diet. Linoleic acid is one of the EFAs and should be provided at >0.5% DM.

Finally, there are minerals that must be present in a cat’s nutrient profile in order to lay the foundation for good skin and haircoat quality. Copper deficiency causes a dull, dry haircoat with patchy hair loss and loss of normal hair pigment. The coat takes on a “washed out” appearance. Zinc deficiency causes hair loss, skin ulcers, and areas of skin thickening and cracking, particularly over joints and on foot pads. The skin-related signs of mineral deficiency rapidly resolve with appropriate levels in the diet.

Another important way that nutrition can affect a cat’s skin and haircoat is when the cat is dealing with inflammatory or itchy skin disease. In these cats, providing omega-3 fatty acids (FAs) from fish can make a dramatic difference. The omega-3 FAs modulate production of chemicals in the body that contribute to inflammation and itching in the skin. Omega-3 FAs have the greatest impact if the underlying causes of itchiness are controlled (e.g. flea infestation). In cats with allergies, omega-3 FAs may allow for a dose reduction in any medications needed to control symptoms. Fortunately, veterinary products are available to provide appropriate supplementation of omega-3 FAs for your cat and can be reviewed with your veterinarian.

The data clearly show a close relationship between nutrition and healthy skin and haircoat in cats. It is important to prevent malnutrition—both by preventing deficiencies of nutrients as well as preventing excesses of nutrients. Your veterinarian is the very best source of information and guidance for choosing the most appropriate nutrient profile for your cat. Be sure to ask your veterinarian about any supplements you are considering. Nutrition for optimal health, wellness, and skin and haircoat quality is more involved than you may think!