http://www.your-pets-r-family-2.com/ When fed the same food for long periods of time many dogs and cats will develop signs of intolerance to the foods protein source. If your veterinarian has diagnosed a food allergy they will most likely place your pet on a diet with a unique protein and carbohydrate. These are sometimes referred to as “novel” proteins or carbohydrates. A unique protein is one that your pet has never been exposed to. Originally Lamb and rice diets were the common choice but over time this formula gained popularity to such a degree that many of the pet food manufacturers began introducing it into their product lines. The result is that most dogs and cats have been fed lamb as a protein source at some point.