Diet and skin disease in dogs and cats

Dietary factors have a major role in the maintenance of healthy coat and sk in, and are significant in the etiology and therapy of certain skin disease s. Nutritional deficiencies are now uncommon as a result of the widespread feeding of complete and balanced pet foods. Deficiencies of (n-6) polyunsat urated fatty acids, zinc and vitamins, however, do arise in certain animal- or product-related instances. Supraphysiologic doses of vitamin A have bee n used in the management of vitamin A-responsive dermatosis in Cocker spani els; other keratinization defects and seborrheic conditions may respond to retinoid therapy. Much interest has been paid to the therapeutic value of p olyunsaturated fatty acid supplements in the management of dermatologic con ditions associated with hypersensitivity reactions or keratinization defect s. These studies have generally yielded disappointing results, which may re flect shortcomings in the design of some trials. Nevertheless, a placebo-co ntrolled, double-blind, cross-over study has demonstrated a clear benefit o f high dose (n-3) fatty acids in the management of pruritic skin disease. T here is also preliminary experimental evidence that specific dietary (n-6): (n-3) fatty ratios are useful in the dietary management of inflammatory dis eases. Although results of controlled clinical trials are awaited, the argu ment exists that it is the absolute amount of (n-3) fatty acid intake rathe r than ratio that is responsible for potential health benefits.