Just some more information
I happened on to this researching the internet for my own dog, and thought about what was going on with your dog. So I am posting this for some information, and maybe to bring it up to your vet too. Just maybe another possible reason. It goes as follows below:
Over the years, I have seen this condition in pets that I have not found described in veterinary textbooks.
Dogs, particularly those that are all or part German Shepherd and between the ages of one and one-half and four years of age may suddenly and violently attack a portion of their body as if it itched severely. The most commonly affected area is the end of the tail, but sometimes a paw is affected. These are generally high-strung dogs with other neurological problems (like tail chasing or fly snapping). This problem has been called self-mutilation syndrome. It may be a form of seizure similar to frontal lobe epilepsy. I have not observed this problem in horses. When it does occur in horses, it is thought to be an obsessive-compulsive behavior trait. Some of these dogs and horses will respond to antiseizue medications (Phenobarbital, Primidone, Dylantin). Other cases respond well to the tricyclic antidepressant, chlomipramine (Clomacalm) and antidepressant, amyltriptiline (Elavil). Prozac is also effective in some dogs. Although Phenobarbital and Primidone are often effective, long-term use of these drugs can cause liver damage. It may take 5-8 weeks before an improvement is noticed. There is anecdotal evidence that placing these dogs on a greatly reduced protein diet may also be beneficial.
Last edited by Elaine H; May 13th, 2006 at 12:53 AM.