This 'Harmless' Obsession Can Quickly Degrade to Infections, Even MRSA

Analysis by Dr. Karen Shaw Becker

Story at-a-glance -

  • Acral lick dermatitis, or lick granuloma, is an injury to a dog’s skin caused by excessive licking
  • Common locations for a lick granuloma are the tops of the front legs, between the elbow and toes, and on the sides of the ankles or heels
  • There are many causes for this condition — the most common is itchy skin caused by allergies
  • Effective treatment of acral lick dermatitis involves identifying and addressing the underlying cause, along with healing the wound
  • There are many effective natural remedies for healing the granuloma; preventing recurrence typically involves environmental enrichment to address emotional factors

Acral lick dermatitis (ALD), also known as lick granuloma, is an injury to the skin caused by excessive licking. The word "acral" refers to a limb or other extremity. A granuloma is a focal-thickened area of ulcerated inflammation.

When a dog constantly licks a certain spot on his body, it eventually becomes inflamed. The skin thickens and the area never gets a chance to heal because the dog won't leave it alone. In addition, the licking and inflammation makes the spot itchy, which causes more licking and creates a vicious cycle of itching and licking.

The next thing you know, a secondary problem develops, like a bacterial infection or ruptured hair follicles or apocrine sweat glands. The secondary condition can make the itch much worse and exacerbate the itch-lick cycle.

Common locations for a lick granuloma are the top of the front legs, between the elbow and toes, and on the sides of the ankles or heels. Signs your dog may have a lick granuloma include constant licking and chewing of the area, missing hair or baldness, ulcerations, thickened skin and hard, raised bumps that look like callouses.

Occasionally, past trauma to the affected area can cause excessive licking due to residual pain or neuralgia, like nerve tingling. Lick granulomas are most often seen in middle-aged, large-breed dogs, especially Doberman Pinschers, golden and Labrador retrievers, Great Danes, Irish and English Setters, Akitas, Dalmatians, Shar Peis and Weimaraners.

Causes of Acral Lick Dermatitis

There are several underlying reasons for this form of dermatitis to occur. It's likely that in many cases, itchy skin caused by allergies triggers the excessive licking, which then progresses to a lick granuloma. However, a painful condition can also set it off. For example, past trauma from a broken bone that results in residual arthritis.

Post-surgical discomfort, a foreign body such as a sliver, an insect bite, nerve damage and, rarely, focal cancer can be the inciting cause. Other possible triggers include a bacterial or fungal infection, skin mites or a hormone imbalance.

In addition to physiological causes, incessant licking is also a common symptom of compulsive disorder in dogs. The act of licking may trigger the release of endorphins, which are natural substances that promote a sense of well-being. The dog learns that licking brings about this pleasant feeling, so he keeps licking. There can also be psychological factors involved in obsessive licking, including boredom, stress and separation anxiety.

Diagnosing Lick Granuloma

It's extremely important to find the root cause of your dog's licking so it can be treated effectively along with the skin wound. Your veterinarian should rule out any potential underlying allergic disease first, because that's the most common reason dogs lick and dig at their skin.

A dog with recurrent skin or ear infections, hotspots or itching in other areas of the body should be evaluated for a generalized allergic condition. A possible allergy to fleas, food or something in the dog's environment should also be investigated. Several tests may be necessary to definitively diagnose lick granuloma, including deep skin scrapings and fungal and bacterial cultures to check for infection. Occasionally, skin biopsies of the inflamed tissue are also necessary to rule out conditions with similar symptoms.

Most dogs with acral lick dermatitis have a bacterial infection. I can't stress enough the importance of identifying the specific organism (bacterium) present in order to determine the most effective treatment — especially because these bacteria are often resistant to antibiotics, and a significant percentage are methicillin-resistant (MRSA).

Other necessary diagnostics may include x-rays to check the health of the bones beneath the irritated skin, bloodwork to check for endocrine diseases and tests for the presence of parasites.

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Treatment Options

In addition to treating the wound, it's critically important to also deal with the underlying physical and/or emotional causes of your dog's licking. Otherwise, the problem is likely to recur. To keep your dog's mouth away from the wound while it heals, an Elizabethan (E-collar) or BiteNot collar will probably be necessary. The collar will also help curb the behavioral component of obsessive licking by breaking the cycle.

Sometimes "out of sight, out of mind" also works, so applying a light, nonstick bandage may keep your dog from licking the wound. However, many dogs simply chew the bandage off and swallow it, so don't take this approach if your dog will eat the bandage! What's most important is figuring out how to prevent your dog from continuing to lick the wound. The sooner the licking stops, the faster your dog's wound will heal.

Keeping the wound clean is imperative. I recommend disinfecting with a topical solution called Betadine twice a day. After disinfecting the wound, I recommend using a topical remedy to speed healing. No one remedy works for every dog, so my advice is to try different topicals until the wound is healed. A few options to consider:

Some veterinarians prescribe antidepressants or anti-anxiety drugs, either short- or long-term, for dogs with recurring lick granulomas. However, these drugs are powerful and have side effects, so I only consider them as a last resort in cases in which I'm sure there's a psychological component involved.

I recommend starting with safer options, such as L-theanine, St. John's Wort, gamma-aminobutyric acid (GABA), 5-Hydroxytryptophan (5-HTP) and Chinese herbs that naturally help calm dogs down. Cannabidiol (CBD) oil can also be beneficial for these patients.

Environmental Enrichment for Dogs With Acral Lick Dermatitis

It's also important to address any psychological or emotional factors that may be contributing to your dog's obsessive licking. All dogs, and especially large breeds need lots of physical activity, so that's a good place to start.

Most dogs will develop behavior problems of one kind or another if they spend a lot of time alone and don't get much exercise. Rigorous daily aerobic exercise is one of the best ways to break the lick cycle. If your dog doesn't have a "job" or something she really enjoys doing, now is the right time to look into a fun and engaging activity, like nose work.

Changes in your dog's environment that create stress can also trigger abnormal behaviors, including the desire to do some obsessive licking. For example, if another pet in the family has died or if a new pet has been added, it can create stress for your existing dog.

Make sure everyone in the family pays extra attention to your dog when there's any sort of change in the household dynamic that could precipitate a bout of licking. Address any conflicts in your dog's life, for example, separation anxiety, problems between animals in the home or long periods of confinement or boredom.

In addition to making sure your pet is well-exercised, he needs playtime and activities that stimulate his brain, as well as a nutritionally balanced, species-appropriate diet, a consistent daily routine, and clear and regular communication from you.

Crating or otherwise confining a large-breed dog for several hours a day is asking for a problem, especially with dogs who are already displaying anxiety-based behaviors like incessant licking. If you're gone from home for long periods during the day, consider doggy daycare or a dog-walking service to give your pet opportunities for companionship and exercise while you're away.

Prevention Tips

The best way to avoid a painful, infected lick granuloma in your dog is to deal with the obsessive licking behavior as soon as you become aware of it. If you see a wet spot on her fur several days in a row, that's reason enough to address it.

Some lick granulomas can develop very quickly, within a matter of hours. Others take longer to appear. If you can avoid it, don't wait until there's an obvious injury or irritation to your dog's skin before seeking advice from your veterinarian and initiating some of the suggestions I've offered here.

Get in the habit of running your hands over your dog, especially down the legs to check for damp fur. When you're around the house, if your dog spends time outside your line of vision, check on him frequently to ensure he isn't hiding an obsessive licking habit from you.

If he's licking a certain spot but there's no injury yet to the skin, try wrapping the area lightly with an Ace bandage to discourage further licking. You can put a few drops of lavender oil on the bandage, massage a drop of lavender into the skin or put a dab of the homeopathic remedy arnica gel over the area.

You'll still need to see your veterinarian to identify the underlying reason for the licking. But in the meantime, anything you can do to prevent your dog from self-injury will be beneficial.