Issue Description 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. Other Names Lick Granuloma
Causes The cause of a lick granuloma is most often
psychogenic and is considered to be a form of canine
obsessive-compulsive disorder, but other causes include bacterial or
fungal infections, demodectic mange, trauma causing nerve damage,
allergies, or joint disease. Hot spots may also lead to the formation
of lick granulomas. Many large breed dogs appear to be predisposed.
Psychogenic causes include boredom, stress, 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, causing a secondary problem.
Commonly Affected Breeds
Irish Setter and other setters
German Shepherd Dog
Keep in mind that any breed of dog can develop a lick granuloma,
including mixed breeds
Symptoms Lick granulomas are skin wounds typically
located on the distal area of the front leg or hind leg of a dog. Some
dogs may have more than one lick granuloma at a time. These lesions
usually appear as firm, raised, hairless areas of skin that may be
hyperpigmented, or darkened with pigment, due to the dog's chronic
licking of the area. The center of the lesion is usually ulcerated,
red, and moist, or may be covered by a scab.
Diagnosis 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. 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.
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.
Treatment Treatment of the primary cause, if known, is
essential. The dog should be tested for allergies, and treated
accordingly if positive (fatty acids, antihistamines, hypoallergic
diet, etc). It may also be necessary to check thyroid levels as
hypothyroidism seems to play a role in some cases, particularly in
black Labrador retrievers; thyroid medication often will resolve the
problem if it's due to hypothyroidism.
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
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.
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 surgery,
radiation therapy, and acupuncture. It is important to note that many
dogs will lick at another leg, creating a new lick granuloma, if they
are prevented from licking at the original one while it heals.
Overall, lick granulomas are very difficult to treat, with control
only being achieved in about 65 percent of cases.