Primal Pet Foods
Why is my pet is itching, scratching or biting themselves excessively?

Whenever your pet is itching, scratching or biting themselves excessively, we recommend consulting your holistic veterinarian or pet nutritionist to determine the direct cause of this behavior.

Often times, animals exhibit this behavior due to food allergies. Food allergies are typically indicated by your pet chewing the tops and/or bottoms of their feet as well as chewing at the base of the tail (where the tail meets the body). If your vet or nutritionist determine that your pet has a food allergy, we suggest following an isolation diet to determine those food products that may be causing your pet discomfort. By following a strict diet of single source protein and avoiding all grain sources, determining the direct cause of your pets excessive behavior will be easier to isolate.

Excessive itching, scratching and or biting may be due to environmental allergies and/or excessive toxins in the body as well.

(from the Primal Pet Food Site)