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, near the carpus (wrist) 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 dogs respond to that by licking; this may serve to further increase the itching or tingling. Very shortly, a vicious cycle develops, creating a habit much like a child sucking its thumb. Even if the problem that initiated the itching or tingling sensation is gone, the habit of licking continues.
Certain breeds are more likely to get lick granulomas. They occur most commonly in German Shepherds, Doberman Pinschers, Great Danes, Labrador Retrievers, and Irish Setters, but it is possible in any breed. In addition, male dogs are twice as likely to do this when compared to female dogs.
There is no agreement on the reason that some dogs develop this compulsion to lick. There are three basic views on the subject. Some see it as a primary skin disorder. Some see it as a behavioral problem, and some see it as a neurologic disease involving the nerves in the area. It is likely that most lick granulomas have more than one cause or a single cause with one or more contributing problems.
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. However, certain skin tumors, parasites, embedded foreign bodies, and allergies can create lesions that look very similar. In addition, trauma that causes bone fractures or nerve injury can also lead to constant licking, creating a similar lesion. 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.
Many approaches have been taken to this problem, and none have been successful in all cases. Often, success is only achieved after several “trial-and-error” attempts have been made.
The approach to treatment generally begins by trying to eliminate potential psychological factors. Boredom and stress are important issues that should be addressed. It has been suggested that another dog be acquired to keep the affected dog distracted from the licking cycle. Since this approach may not be successful, it should be limited to situations in which acquisition of another dog has already been a consideration.
If no initiating cause can be found and eliminated, various medications are used. These fall into two categories: drugs to deaden feeling or relieve inflammation in the area and mood-altering drugs. In many cases, a drug in each category will be used simultaneously as a means of attacking the problem from both angles.
Some dogs respond best with combination drug therapy and the use of restraint collars. These collars are wide enough to obstruct the dog’s access to the lick granuloma. They may be needed for 6-8 weeks.
Many dogs develop secondary bacterial infections within the lick granuloma. Long-term antibiotic therapy of 6-8 weeks duration can be helpful in some situations.
Some rather aggressive and unusual treatments have been used with variable degrees of success; improvement is seen in 20-40% of cases. These alternative treatments include radiation therapy, surgical excision of the lesion, cryosurgery (freezing), and the injection of cobra antivenin.
This is one of the most difficult medical problems that happen to the dog. Because the initiating factor is usually not identified and because there is such a strong habit that forms, treatment can be very frustrating. Regardless of the initial treatment chosen, it is always possible that it will not be successful. If that happens, it is important that you communicate that to your veterinarian so another avenue can be pursued.