Also Known As: Acral lick dermatitis, acral lick furunculosis, lick granuloma
Transmission or Cause: The causes of acral lick granulomas include infections caused by bacteria, fungi, or mites; allergies, cancer, joint disease, or previous trauma; or an obsessive-compulsive disorder caused by boredom in some dogs. Dogs are provoked by these conditions to lick an area until they cause hair loss and erosion of the superficial skin layers. The consequence is further inflammation, which then results in more licking. With time, excessive licking can cause secondary infections, thickening of the skin, and changes in skin-color.
Affected Animals: Acral lick granulomas may affect dogs of any breed and gender, however, males and dogs that are five years and older are more often affected. Breeds predisposed to this condition include Great Dane, Doberman Pinscher, Labrador Retriever, Golden Retriever, German Shepherd, and Irish Setter.
Overview: A commonly seen skin disorder of dogs, acral lick granulomas are skin wounds that are worsened by a dog's constant licking of the affected area. Because the repeated licking hinders healing of the lesion, dogs must be prevented from licking the area until the wound has healed completely. Acral lick granulomas have a wide variety of possible causes. The disease is often bothersome to pets as well as their owners. A veterinarian can implement appropriate medical therapies to treat the lick granuloma and to prevent recurrence.
Clinical Signs: Lick granulomas are skin wounds typically located on the lower portion of the front or hind leg of a dog. Some dogs may have more than one area affected at a time. These lesions usually appear as firm, raised, hairless areas where the skin may be darkened due to the dog's continued licking of the area. The center of the lesion is usually ulcerated, red, and moist, or may be covered by a scab.
Diagnosis: Diagnosis of acral lick granuloma and its cause requires a thorough history and physical examination. The following tests may be performed in order to determine the underlying cause of excessive licking: microscopic evaluation of cells from the wound, biopsy, allergy testing, and/or x-rays. Underlying conditions of the lesions include joint disease, cancer, bacterial or fungal infection, Demodex mite infection, previous trauma, allergies, and/or psychogenic licking. Prognosis: Because acral lick granuloma is difficult to cure, veterinarians usually give it a guarded prognosis. Dogs that receive early treatment have a better prospect of recovery than dogs with chronic conditions.
Treatment: Treatment of acral lick granuloma requires addressing the underlying cause of the lesions. Bacterial infections, for example, are treated with antibiotics. Arthritis is treated with pain management and joint therapy. The obsessive compulsive component of the disease is more difficult to treat. The dog may be prevented from licking the area by using a type of mechanical blocking device such as a collar, muzzle, or bandage. Oral antidepressant or anti-anxiety medications may be helpful. A topical product may be used to decrease the itchiness of the area and aid in the healing process. If the lesion is small, it may be surgically removed, but recurrences are frequent. Radiation therapy has been tried in some cases, but its rate of success is poor. Laser surgery may be helpful in selected situations.