Some medical conditions require specific dietary modification. For instance a cat who has urinary issues often benefits from a diet that prevents crystals from forming in the bladder. Dogs who have had problems with pancreatitis do better on low fat formulations. Pets with kidney conditions require diets restricted in phosphorous and protein to help extend their lives.
Because these therapeutic diets are designed to treat or control specific conditions they are only available through veterinarians just as a medication would be.
At Blue Cross Animal Hospital we recommend and stock therapeutic diets made by two companies that do a great deal of nutritional research developing these therapeutic diets. Both Hills and Medi-cal are world leaders in producing therapeutic diets.