Lick granuloma

A lick granuloma, also known as acral lick dermatitis, is a skin disorder in dogs resulting from an urge to lick the lower portion of the leg. The lesion from the incessant licking is a thickened, firm, oval plaque.

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Causes

The cause of a lick granuloma is most often psychogenic and is considered to be a form of canine obsessive-compulsive disorder^[1], but other causes include bacterial or fungal infections, demodectic mange, trauma causing nerve damage, allergies, or joint disease. Large breed dogs appear to be predisposed.^[2]

Psychogenic causes include boredom or separation anxiety. Lick granulomas are especially seen in large active dogs left alone for long periods of time. The condition becomes a vicious cycle - erosion of the skin from licking leads to pain and itching, which leads to more licking. One theory is that excessive licking causes endorphin release, causing an addiction to licking. The lick granuloma often becomes infected with bacteria.

Commonly affected breeds

• Dobermann
• Great Dane
• Labrador Retriever
• Irish Setter
• Golden Retriever
• German Shepherd Dog^[3]

Treatment

Treatment of the primary cause, if known, is essential. In psychogenic cases, dealing with psychological factors is most important. Factors should be identified such as being left alone all day, being confined, and changes in the household. Correction of these causes may include increased walks, avoiding confinement, and more interaction in the home.

Drugs may be used until behavior modification has had time to take effect. Antidepressants are most commonly used, including doxepin, amitriptyline, fluoxetine, and clomipramine. If the psychological factors are not corrected, the dog will usually relapse after the drugs are discontinued. Endorphin blockers such as naltrexone can be used to reduce addiction to licking, or endorphin substitutes such as hydrocodone may decrease the urge to lick.^[3]

The lesion should also be treated. Licking can be prevented by the use of Elizabethan collars, bandages, or antilicking ointments (which are bad tasting). Topical medications such as corticosteroids or DMSO may be effective if used early. Small lesions may be injected with triamcinolone or methylprednisolone. Oral antibiotics are used to control infection. Surgery may be performed to remove whole lesions, but there is risk of continued self mutilation to the area afterwards. Other potential treatments include cryosurgery, laser, radiation therapy, and acupuncture.

Overall, lick granulomas are very difficult to treat, with control only being achieved in about 65 percent of cases.^[4]

References