Lick Granuloma in Dogs: Causes, Signs, Solutions

When dealing with a lick granuloma, dog parents may find themselves a bit discouraged. Integrative veterinarian Dr. Julie Buzby explains why getting the spot to heal can take some time, and treatment may involve some trial and error. Find out what lick granulomas are, why they happen, and what you and your vet can do to help your dog.

It’s not uncommon for dogs to lick themselves. Perhaps they are soothing an area of minor irritation like a bug bite. Or maybe they are trying to get every last bit of leftover flavoring off their fur after chomping on a tasty chew they were “holding” with their paws. Whatever the reason, licking does happen sometimes.

However, frequent licking is concerning. Especially if it is concentrated on one area, excessive licking can cause problems for your dog. Acral lick granulomas are one issue that can arise if your pup persistently licks a particular spot.

What is a lick granuloma in dogs?

A lick granuloma, also known as acral lick dermatitis, is a skin condition that can occur when dogs self-traumatize an area by licking too much. The term “acral” refers to the extremities. Because lick granulomas occur only in places a dog can reach to lick, the most common affected area is the top of the front legs, usually near the carpus (wrist) or paw.

What does a lick granuloma look like?

In the early phases of a lick granuloma, you may notice a well-defined wet spot with some redness (i.e. erythema) and hair loss (i.e. alopecia) on your dog’s front leg. This general appearance also goes with a type of skin infection known as moist dermatitis—sometimes called a hot spot. However, as a result of the excessive licking, lick granulomas extend deeper into the skin than mild superficial skin infections.

As time goes on, lick granulomas can appear deeply red or even eroded and ulcerated. Often, they can have distinct borders and an oval or round shape. Over the course of a few weeks, a lick granuloma can become thickened as the body lays down scar tissue in an attempt to heal the abnormal area. Thick crusts and plaques can also form over or around the granuloma.

What causes a lick granuloma in dogs?

The causes of lick granulomas can usually be generalized into two categories: allergies and behavioral conditions. We often never find out the specific inciting incident that starts the formation of the granuloma. Dogs may begin to excessively lick a certain area for a variety of reasons, and if there is visible irritation we may not see it under the fur.

Dogs who develop lick granulomas may even suffer from a combination of BOTH allergies and behavioral issues!

Allergies

Skin allergies can be triggered by any number of factors including:

• External parasites (fleas, ticks, etc.)
• Environmental allergens like dust and pollen
• Certain foods

Exposure to allergens can cause intense skin inflammation and itchiness. Unfortunately, this can lead to an “itch-lick cycle.” The dog licks an itchy spot, which causes some mild moist dermatitis. That dermatitis is itchy, so the dog licks it. Rinse and repeat.

For some dogs, licking an itchy area can also trigger an endorphin release. This helps the dog relax and may alleviate some discomfort coming from the areas of damaged or inflamed skin.

Behavioral concerns

The fact that licking releases soothing endorphins may also contribute to lick granulomas in dogs with behavioral issues. Dogs who suffer from separation anxiety are stressed when their family is away, so licking may help them calm down.

In the same way, repetitive licking as part of obsessive compulsive disorder (i.e. canine compulsive disorder) can lead to acral lick granulomas. A dog may constantly lick a spot as a soothing habitual action.

Additional causes

Besides allergies and behavior problems, lick granulomas may also result from:

• Pain or abnormal sensations associated with osteoarthritis in dogs
• Focal skin infections
• Bites or other wounds
• Foreign bodies like thorns stuck in the skin
• Localized skin cancers or benign tumors

Which dogs tend to get lick granulomas?

As you can gather from the list of causes, there is going to be an overlap between the dogs who are prone to allergies and/or behavioral problems and those who develop lick granulomas. And while any age, size, and gender of dog can develop lick granulomas, they tend to be more common in large breed dogs.

Predisposed breeds include:

• Boxers
• Doberman Pinschers
• German Shepherds
• Golden Retrievers
• Great Danes
• Irish Setters
• Labrador Retrievers
• Weimaraners

Regardless of whether or not your dog has one of these predisposing factors, if you suspect that your dog has a lick granuloma or other skin problem, make an appointment with your vet. The sooner you get a diagnosis, the sooner you can start treatment for the lick granuloma.

How will the vet diagnose a lick granuloma?

At the appointment, your vet will probably start out by carefully evaluating the suspect area on the skin. Many times, the vet will presumptively diagnose your dog with an acral lick granuloma. He or she will base the diagnosis on the classic appearance of the spot on the skin and history of seeing the dog excessively licking the area.

However, despite having the textbook appearance of a lick granuloma, occasionally the spot can actually be something else, such as a mast cell tumor in dogs. Your vet may recommend diagnostic testing to make sure the presumed lick granuloma isn’t something more sinister.

Fine needle aspirate

One such test is a fine needle aspirate (FNA). During an FNA, the vet uses a small needle to collect some cells from under the skin. Then he or she will examine the cells using a microscope. These cells can often tell us whether the spot is cancerous or benign.

Biopsy

For cases where a fine needle aspirate does not give a conclusive answer, or looks suspicious for a cancerous mass, skin biopsies can give more information on what the spot may be. Often performed under general anesthesia, a skin biopsy involves cutting a small portion of the area out and sending it to a laboratory for testing.

Biopsy results are generally more specific and reliable than those from FNAs, but it is a more invasive procedure.

Cytology

Your vet may also want to do a skin cytology or skin impression test. A study published in the journal of Veterinary Dermatology indicated that 97% of lick granulomas have a secondary bacterial infection. Cytology is similar to a fine needle aspirate, but only evaluates the most superficial cells, rather than cells inside the lesion or underneath the skin.

For a skin cytology, the vet will scrape some material off the surface of the skin lesion and apply it to a microscope slide. For a skin impression test, the vet presses a glass slide against the abnormal area on the skin. Alternatively, sometimes clear tape can be pressed to the lesion to pick up cells, then placed onto a slide. The vet will then evaluate the material on the slide for signs of infection or abnormal cells.

Sometimes the vet will suggest additional testing. This may involve:

• Skin scrape to look for demodex mites or other irritants
• Fungal culture to check for ringworm
• Bacterial culture to determine which bacteria are present and guide antibiotic selection

What is the treatment for a lick granuloma?

Once your vet diagnoses your dog with a lick granuloma, he or she will discuss treatment options. Unfortunately, there is no one-size-fits-all treatment for lick granulomas. So this may mean it will take some trial and error to find the right combination of treatments. Keep in mind that you must not only treat the acral lick granuloma itself, but also the underlying conditions that led to it.

Antibiotics

Since we know almost all lick granulomas have a bacterial infection, most require antimicrobial therapy for treatment.

Constant licking breaks down the surface of the dog’s skin, allowing bacteria that would normally populate the surface of the skin to migrate deeper in the skin and cause an infection. Also, mouth bacteria can enter the area of broken skin from the licking. Because these are often deep infections, oral antibiotics may be prescribed for up to eight weeks or more.

Topical products

In addition to oral antibiotics, topical medications that contain antibiotics can also be extremely useful. In some cases, they may reduce the need for systemic antibiotics.

Some veterinarians will even use topical ear medications like Claro or Synotic to treat lick granulomas. These products contain combinations of antibiotic, antifungal, and anti-inflammatory ingredients that can treat the infection while providing itch relief.

Anti-inflammatories

As you may imagine by their irritated, sometimes ulcerated appearance, lick granulomas are associated with significant inflammation. Thus, the vet might prescribe a course of anti-inflammatory medication to help to break the itch-lick cycle. Some popular options include NSAIDs like carprofen for dogs or steroids like prednisone for dogs.

These medications are helpful because they make the dog feel better and decrease further trauma to the area. However, it is important to keep in mind that typically you also need to address the underlying cause and treat the secondary infection to have the best chances of the lick granuloma resolving.

Important note: Steroids and NSAIDs should not be given together to dogs. The combination of these medications can have dangerous side effects.

Elizabethan Collars

I know. Nobody likes the “cone of shame.” But preventing a dog from licking is paramount to getting a lick granuloma to heal. I wish I could explain this to my patients, but it is extremely difficult to deter licking without a physical barrier.

Covering the area can sometimes help, but many dogs will chew or lick at the covering. Because lick granulomas are associated with moist dermatitis, leaving on a wet bandage only exacerbates the problem. Additionally, bandages and booties may be chewed off and consumed, potentially causing dangerous foreign bodies.

That is where the Elizabethan collar (i.e. E-collar) comes in. The E-collar creates a physical barrier between the dog’s mouth and paws, preventing licking. Keep in mind that soft E-collars are bendable, and usually don’t effectively limit the dog’s access to the affected area.

Additional treatment modalities

Dogs with acral lick dermatitis may also benefit from:

• Acupuncture for dogs—Placing acupuncture needles around the lick granuloma may lessen the itchiness.
• Laser therapy for dogs—Using a cold laser to apply a low-energy beam of light to the lick granuloma can help speed up healing.
• CO2 laser surgery—Typically, this option is reserved for chronic or non-healing granulomas. Removing scar tissue and dead skin cells from the lick granuloma exposes healthier layers of skin, which makes it easier for other treatment options to promote healing and provide relief.

Control of underlying causes

In addition to treating the actual lick granuloma, it is imperative that you address the underlying cause. If we do not manage the underlying issue, the lick granuloma is likely to recur.

Allergy treatments

There are a plethora of allergy medicines for dogs. Medications like Apoquel and Cytopoint can give itchy dogs some relief by blocking the itch signals the body releases in response to allergen exposure. This does not “cure” the allergy itself, but decreases the symptoms, making dogs scratch and lick less frequently.

Dogs with environmental allergies can also benefit from immunotherapy (i.e. allergy shots). Allergy testing determines the exact allergens the dog reacts to, and vet specialists can then produce immunotherapy injections based on those results. These injections should make the allergic reactions less intense over time.

However, allergy testing and immunotherapy are generally not useful for dogs with food allergies. Instead, most vets will recommend a food trial. This involves feeding a novel protein or hydrolyzed protein diet exclusively for 8 to 12 weeks. If the itching improves significantly, the dog can continue to eat that diet long term.

To pinpoint the exact allergen, you can always reintroduce one suspected allergen (e.g. chicken or beef) at a time. If the dog becomes itchy again, this confirms the dog is allergic to that ingredient. Avoiding that allergen in the future will help control food allergies.

Addressing anxiety

Since anxiety and other behavioral conditions can also cause lick granulomas, your veterinarian may discuss options to help your furry friend relax. Determining that anxiety is the underlying cause may involve ruling out allergies first, so this can take some time and may be frustrating.

Your vet may recommend using medications like fluoxetine or clomipramine to ease your dog’s anxiety. Each individual reacts differently to behavioral medications, and some may have to be given for several months in order to determine whether they will be effective. During that time, you can work on plans for behavior modification. This may include eliminating visual cues that set off your dog’s separation anxiety, mitigating responses to loud sounds like thunder, etc.

Additionally, sometimes focusing on canine environmental enrichment and increasing your dog’s activity can make a big difference. This could involve sending your dog off to doggy daycare for a few hours, going for a longer run or walk, or providing some food puzzle toys. Tiring out your dog’s body and mind can help them stay calm and relaxed.

Arthritis management

Since some dogs lick repetitively in response to pain or abnormal sensation from arthritis in dogs, finding ways to relieve arthritis pain in dogs can be helpful.

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At-home treatment for lick granulomas

In combination with these other treatments, you can try some techniques at home to keep your dog from licking an already established lick granuloma.

In addition to tools like E-collars, noxious topical products like Bitter Apple spray can also be effective because they taste awful. Generally, you would need to apply the yucky tasting substance in small amounts every eight to twelve hours to prevent licking.

Lick granuloma treatment takes time

Even if you do everything right, it is important to keep in mind that some acral lick granulomas can take several months to resolve. Lick granulomas are one of the more frustrating conditions that we treat in veterinary medicine. Most heal slowly, and it can take time to find the right treatment. Unfortunately, some never do fully resolve.

While you are treating your dog’s lick granuloma, periodic check-ins with your veterinarian are vital to the process. He or she may want to recheck the skin cytology to ensure that any skin infection at the granuloma site is responding to therapy. Also, if initial therapies aren’t helping, your vet can come up with a new plan or additional therapies.

Following your vet’s directions is critical. Even something as simple as leaving the E-collar off can set back resolution for weeks, or perhaps months. I know it isn’t fun to need to put an E-collar on your dog, give daily medication, or otherwise change the way you care for and interact with your dog for a period of time. However, if it means getting the lick granuloma to improve, it is worth it.

How can you prevent a lick granuloma?

Knowing how difficult it is to manage a lick granuloma once it is established, it only makes sense that trying to prevent one from starting would be ideal. If you know your dog has allergies, anxiety, or other factors that predispose him or her to lick granulomas, keep these prevention tips in mind:

• Administer prescribed medications as recommended by your vet.
• If your dog suffers from environmental allergies, work with your vet to create a bathing and grooming routine to help remove surface allergens.
• Consider naturally calming treatments and supplements such as Zylkene, Composure Pro, and Solliquin if your dog struggles with anxiety.
• Promptly report any changes to your dog’s level of itchiness, skin appearance, or pain or anxiety levels to your vet.
• Break out the E-collar or lick deterrents if you notice that your dog is starting to constantly lick an area. Then make a vet appointment to get to the root cause of the licking.

Work with your vet

The sooner you can start treatment and the more you stay in communication with your vet, the lower the chance the dog will end up with a chronic or difficult-to-treat acral lick granuloma. Hopefully, with a bit of patience and persistence, your dog will be able to recover quickly and “lick” his or her lick granuloma once and for all!

Has your dog had a lick granuloma?

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