Acral Lick Dermatitis (ALD)

The Problem: What is ALD?

Acral lick dermatitis (ALD), also known as lick granuloma or canine neurodermatitis is a stereotypic behaviour resulting in self-mutilation. A stereotypic behaviour refers to a pattern of movements or behaviours which are repeated without variation and seem to occur for no apparent purpose. Such things as pacing or excessive grooming are common types of stereotypies seen in domestic or captive animals. In ALD the stereotypy is self-licking, chewing or scratching, most commonly on the distal portions of the limbs. The repetitive licking creates areas of hair loss and the production of lesions which may range in size from several centimetres to the entire surface of the limb. The continuous self licking and chewing prevents the lesions from healing and may cause discomfort, pain and, in severe cases, crippling.

Contributing Factors:

ALD is most common in large active breeds, but small dogs may be affected as well. Of the large breeds the Doberman, German Shepard, Great Dane, Golden Retriever, and Labrador Retriever seem to be more predisposed to ALD than other large breeds. It is largely agreed that ALD is a behavioural disorder with many possible origins. The self-licking and chewing acts as a release of tension for dogs which are bored, socially isolated, confined for long periods of time or are physically punished continually by their owners. The self-licking may also be initiated by an overattentive or nervous owner who inadvertently fosters nervous behaviour in their pets. The introduction of new animals or people into the household may also initiate ALD. It is very important if you see your dog licking incessantly that other possible causes are ruled out such as bacterial or fungal infections, neoplasia, trauma, foreign body and allergies which may cause similar symptoms. In order to rule out other causes your veterinarian may need to take bacterial cultures, radiographs, histological examinations or other laboratory tests.

Dealing with ALD: Treatment and Prevention

Unfortunately, ALD is difficult to treat. Many methods of treatment are available, but none are consistently effective. Treatments include: restrictive collars, bandaging, topical corticosteroid creams, surgical excision, radiation therapy and a wide range of behaviour modifying and antiobsessional drugs (antidepressants, antianxiety, etc.). Each of these treatments has varying degrees of success and failure on a case by case basis. However, none of the above address the behavioural origins of the disorder. The treatment may have short term success, but after the bandage is removed or the medication stopped, the self-mutilation behaviour will almost always begin again. Treatment should first begin with behavioural modification and then may be coupled with one of the above treatments on advice of your veterinarian. The owner first must try to identify the stimulus which is causing the dog anxiety and observe the environment/lifestyle of the dog. Is the dog socially isolated with little or no human contact? Is the dog crated for long hours at a time? Is the dog home alone 8+ hours a day? What kind of exercise does the dog receive? Listed are some suggestions which may help prevent the onset of ALD and aid in its treatment:

All of the above suggestions will improve the human-dog bond as well as decrease the stress and anxiety which may lead to behavioural disorders such as canine acral lick dermatitis. Treatment of ongoing ALD requires identification and elimination of causative stimuli, behavioural modification and medical treatment to allow the self induced lesions time to heal.

References

Davis, Lloyd E., Handbook of Small Animal Therapeutics. Churchill Livingstone Inc., 1985.

Dodman, Nicholas E., Shuster, L.E., White, S.E., Court, M.E., Parker, D., Dixon, R. Use of narcotic antagonists to modify stereotypic self-licking, self-chewing, and scratching behavior in dogs. Journal of the American Veterinary Medical Association. 193:7 Oct 1/88 pp 815-819.

Goldberger, Erica G., Rapoport, J.L. Canine Acral Lick Dermatitis: Response to the Antiobsessional Drug Clomipramine. Journal of the American Animal Hospital Association. Mar/Apr 1991. Pp 179-182.

Rivers, Bill, Walter, P.A., McKeever, P.J. Treatment of Canine Acral Lick Dermatitis with Radiation Therapy: 17 cases. Journal of the American Animal Hospital Association. Nov/Dec 1993. Pp 541-544.

White, Stephen, J. Naltrexone for treatment of acral lick dermatitis in dogs. Journal of the American Veterinary Medical Association. April 1990. Pp 1073-1076.

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