Extreme licking of back paw

Question
Good Morning,
I have a 7 yr. old yellow lab.  She starting licking her paw months ago.  We've taken her to the vet $500.00 ago, and still is bad.  We have gotten all the sprays ointments that was recommended.  We have wrapped it, got a (lamp shade collar), put booties on it, and it is red swollen, and to the bone..    Please help we are at our witts end.  The vet said it's probably a bad habit now, but it gets infected and it's so sad to see her like this.  Thank you for your time

Answer
Hi Brenda,

I understand your frustration in getting to the bottom of your dog's problem.

The possible root causes for self-trauma include: anxiety, boredom, stress (such as new member in household or change in the household routine). Licking can develop into an obsessive behavior, as your vet mentioned. You didn't say which medical tests were run, but if a medical cause has been ruled out, you could consider trying "behavior modifying medication" that ease anxiety.
Clomipramine and Amitriptyline are the most common medications prescribed for anxiety disorders in dogs. These medications work best when used in conjunction with behavior management, so you should contact a dog behaviorist after beginning the medication.

Having tried to treat this condition for some time without much success, it might be a good idea to have your dog examined by a Veterinary dermatologist at this point. Just as with human illnesses, sometimes a specialist is needed. You can get a referral from your local vet, or find a Veterinary dermatologist here:

http://www.avma.org/education/abvs/specialty_orgs/default.asp

Since you've tried the Elizabethan collar and bandages without success, you can try using a basket style muzzle on your dog. Basket muzzles are very humane, a dog can even drink water while wearing one.

Even if the underlying problem might be habitual, ongoing treatment of the skin condition is essential. It is very important to continue to treat the frequent secondary bacterial skin infections with appropriate long-term (6 to 8 weeks) antibiotics.

Acral lick dermatitis (ALD), also known as lick granuloma or "canine neurodermatitis" is an obsessive-compulsive disorder resulting in self-mutilation. The Labrador Retriever breed is one of the breeds prone to develop this behavior. You can read more about it here:

http://www.usask.ca/wcvm/herdmed/applied-ethology/behaviourproblems/lickderm.htm...

http://www.dermvet.com/acrallick.htm

Lick granulomas can occur secondary to allergies. You didn't say if your vet has looked into this possiblity. Treatment for the allergy is often successful. It is a good idea to consider allergy testing in dogs with persistent lick granulomas or recurrent ones. The standard treatments for allergies are itch control medications or hyposensitizing "allergy shots". A specail diet may be called for. Skin testing is the most accurate way to diagnose allergies. Veterinary dermatologists frequently do this. Blood testing for allergies is considered to be less accurate but can be substituted when skin testing is hard to arrange.

For really desperate situations, radiation therapy, casts over the area, cryosurgery, and surgical excision have all been attempted.
This condition is frustrating and often will take several approaches to find the one that will work. Keep working with your vet to find a solution to the problem for your dog!

I hope I've been a help!
Best of luck,

Patti