What is a lick granuloma?
A lick granuloma is an open sore on the skin caused by and perpetuated by constant licking. It is generally located on one of the legs, especially near a joint. Typically, the hair will be licked off and the area will be either raw and weeping or thickened and scar-like.
Lick granulomas usually begin with an itching or tingling sensation on the leg. The dog responds to the sensation by licking, which may serve to further increase the itching or tingling. Very shortly, a vicious cycle develops, creating a habit much like a child sucking his/her thumb. Even if the problem that initiated the itching or tingling sensation is gone, the habit of licking continues.
Are there certain breeds that are more likely to do this?
Yes. German Shepherds, Doberman Pinschers, Great Danes, Labrador Retrievers and Irish Setters do this more often than other breeds, though it is possible in any breed. In addition, male dogs are twice as likely to do this than female dogs.
Why does a dog do this?
Agreement has not been reached on the answer to this question. There are three common problems in dogs with lick granulomas:
- There is always some underlying issue that caused the pet to start licking, such as allergies, arthritis or anxiety.
- There is always a behavioral component in the dog exhibiting compulsive licking.
- There is commonly a bacterial component which exacerbates the itching and can be very stubborn to treat. Unless all three components of the condition are addressed, the treatment often ends in failure. In addition, the licking is often episodic and may need repeated rounds of treatment.
How are lick granulomas diagnosed and differentiated from other skin disorders?
In most cases, the diagnosis is made based on the appearance and location of the lesion and the fact that the dog has a compulsion to lick the area. We will frequently perform a skin scrape to rule out mites and a skin cytology to evaluate for infection. However, certain skin tumors, parasites and embedded foreign bodies can create lesions that look very similar. Therefore, if the diagnosis is in doubt or if the dog does not respond well to initial treatment, fungal cultures, radiographs (X-rays) and biopsies may be recommended.
How are lick granulomas treated?
The approach to treatment generally begins by trying to eliminate potential medical and psychological factors. Dogs respond best with combination drug therapy and treatment of the underlying condition, if it can be uncovered. Allergies such as environmental (pollens, grasses) or food (proteins like chicken or beef) are common causes of the underlying itchiness. Boredom and stress are important issues that should be addressed. It is also important to consider underlying conditions that may be causing pain or an underlying allergy.
Commonly, dogs have secondary bacterial infections within the lick granuloma. Long-term antibiotic therapy for six to eight weeks is sometimes necessary, but long-standing, scarred lesions can require four to six months of antibiotic therapy. Anti-itch medications are frequently used to break the cycle of overlicking. Anti-anxiety medications are also used in cases where the licking appears to be behaviorally caused.
Amitriptyline is recommended in combination with hydrocodone to help break the compulsive component of the cycle and relieve pain. All dogs have secondary bacterial infections within the lick granuloma. Long-term antibiotic therapy for six to eight weeks is necessary, but long-standing, scarred lesions can require four to six months of antibiotic therapy.
There is a fairly good success rate with this combination treatment. The medications are gradually weaned down one at a time once the lesion is gone. Remember, however, this disease can be episodic and treatment may need to be repeated down the road.