What is a lick granuloma?
A lick granuloma is an open sore on the skin caused and perpetuated by constant licking. The correct medical term for this problem is Acral Lick Dermatitis. It is generally located on one of the legs, usually near the carpus (wrist) joint. Typically, the hair will be licked off and the area will be either raw and weeping or thickened and scarred.
Lick granulomas usually begin with an itching or tingling sensation. The dog responds to this by licking which serves to increase the itching or tingling further. A vicious cycle quickly 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 licking habit continues.
Are there certain breeds that are more likely to do this?
Yes. German Shepherds, Dobermans, Great Danes, Labrador Retrievers, and Irish Setters probably develop lick granulomas more often than other breeds, but any breed is susceptible. In addition, male dogs are twice as likely to develop these lesions than females.
Why does a dog do this?
There is no clear answer to this question but there are three basic views on the subject. Some experts consider it to be a primary skin disorder, while others see it as an allergic problem, or as a neurologic disease involving the nerves in the area of the affected skin. It is likely that most lick granulomas have more than one cause or a single cause with one or more contributing factors. Often aching arthritic joints can be a contributory factor.
How is this condition 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 observation that the dog has a compulsion to lick the area. However, certain skin tumours, 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.
How is a lick granuloma treated?
Many approaches have been attempted, but none have been successful in all cases. Often, success is only achieved after several “trial-and-error” attempts.
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 even been suggested that another dog be acquired to keep the affected dog company and thus distracted from the licking cycle. Since this approach may not be successful, it should only be considered in situations where you have already thought of acquiring another dog and not as a primary line of treatment.
If no initiating cause can be found and eliminated, various medications are used. These fall into two categories: (1) drugs which reduce sensation or relieve inflammation or (2) drugs which affect the mood of the dog. In many cases, a drug in each category will be used simultaneously as a means of attacking the problem from two angles.
Some dogs respond best to combination drug therapy and the use of restraint collars. These collars (often called Elizabethan collars because of their appearance) are wide enough to stop the reaching the affected area to lick. It may be necessary for the dog to wear the collar for 6-8 weeks because skin conditions take a very long time to heal.
Many dogs develop secondary bacterial infections within the lick granuloma so long-term antibiotic therapy (6-8 weeks) may be helpful in some cases.
Some alternative treatments have been used which include radiation therapy, surgical excision of the lesion, cryotherapy (freezing), or intralesional injection of a long acting corticosteroid. The success rate is very varied and improvement is reported in 20-40% of the cases. These approaches are rather radical and usually employed when other methods fail to be successful.
What is the prognosis?
Lick granuloma is a difficult condition to treat successfully. It is frustrating because the cause is rarely identified and there is a strong psychological component to this condition. Remember that the initial course of treatment may be unsuccessful and that other avenues can be pursued once a lack of response has been observed. The trial and error approach, although tiresome, will usually ultimately result in success.