Some dogs lick the same spot on a leg over and over until the hair is gone and the skin turns into a raised, shiny or raw patch. This is called a lick granuloma, or acral lick dermatitis (“acral” means on the lower legs or feet). It can be stubborn, and it often comes back if only the sore itself is treated.
This guide explains what drives the licking, what your vet will look for, and why treatment usually needs several steps at once.
What a lick granuloma looks like
A review for veterinarians calls acral lick dermatitis a common skin disease that is often hard to manage. Constant licking leads to raised, thick plaques that can ulcerate, and they usually sit on the lower legs. [1]
In plain terms, look for:
- A raised, thickened patch on the lower leg or paw
- Hair loss over the area
- An open sore (ulcer) on the patch
- A dog who keeps going back to lick that one spot
Why it happens: the itch-lick cycle
Licking irritates the skin, the irritated skin itches or hurts, and the dog licks more. The same review lists many possible underlying causes that start this cycle: [1]
- Allergies: atopic dermatitis, food allergy and flea allergy
- Orthopedic or nerve problems, such as joint pain
- Parasites, such as Demodex mites
- Infections, bacterial or fungal
- Tumors
- Behavioral causes, including compulsive disorder
The review adds that other factors, above all secondary infection, keep the itch-lick cycle turning. [1] So even when licking started for one reason, infection in the sore can keep it going.
For more on itch, see why is my dog so itchy? and dog paw problems.
Is it a behavior problem?
Sometimes. A 2022 veterinary case report describes compulsive disorder in dogs as the constant, time-consuming repetition of a behavior that has come loose from its setting and serves no clear purpose. The authors list acral lick dermatitis among these behaviors, alongside circling, barking, fly biting and self-injury, and link them to conflict, frustration and rising anxiety when a dog cannot cope with stress. [2]
But a lick granuloma should not be written off as “just behavior.” A report on six dogs with lesions that looked like acral lick dermatitis found the real causes were lymphoma, an orthopedic pin, deep bacterial infection, a mast cell tumor, leishmaniasis and a likely fungal infection. [3] The authors point out that the condition is often assumed to be behavioral, yet other diseases can produce similar sores on the lower legs. [3] That is why your vet will look for a medical cause first.
Infection can be deeper than it looks
A study of 31 lick granulomas took tissue samples from deep in the lesion. Bacteria grew from 30 of the 31. [4] Forty-eight percent of cases grew bacteria classed as multidrug resistant, and 20% of the deep bacteria were methicillin-resistant staphylococci. [4]
Importantly, swabs from the surface of the sore and cytology often gave a different picture from the deep samples; the surface culture agreed with the deep one in only 8 of 22 cases. [4] The authors concluded that these lesions call for culture of a tissue sample. [4] This is one reason your vet may suggest a biopsy and culture rather than simply trying an antibiotic. See pyoderma in dogs.
What your vet will check
Based on the possible causes above, your vet may: [1][3][4]
- Ask when and where the licking happens, and about itch elsewhere on the body
- Examine the leg, joints and nerves for pain
- Do skin scrapings for mites
- Take a biopsy and a deep tissue culture to check for infection, tumors and other diseases
- Look for allergies if the dog is itchy in other places
How lick granulomas are treated
The vet review says good results depend on dealing with the underlying disease, the secondary infection and any behavioral part, using behavior modification and, where needed, medicine. [1] In other words, three things at once:
- Treat the underlying cause, such as allergy, pain or mites.
- Treat the infection. Because deep infection is common and can be resistant, the choice of treatment is guided by your vet, ideally based on a tissue culture. [4]
- Address the behavior if anxiety, boredom or compulsion is part of the picture. This can include behavior modification and, in some dogs, medicine prescribed by your vet. [1]
A 2021 study describes standard care as whole-body treatment for infection combined with medicine for anxiety, and concludes that the condition needs several treatments working together. [5]
Protect the spot while it heals. Ask your vet how best to stop the licking while the skin heals, and which behavior plan fits your dog. A veterinary behaviorist can help when compulsion is part of the picture.
When to see your vet
Book a visit if your dog:
- Licks one spot so often that the hair is thinning or the skin is red
- Has a raised, thickened or open sore on a leg or paw
- Has a sore that is not healing, keeps reopening, or is getting bigger
- Is limping or seems sore in a joint
- Spends so much time licking that it crowds out normal activities [2]
FAQ
What is the difference between a hot spot and a lick granuloma?
A hot spot is usually a sudden, moist, painful patch. A lick granuloma builds up over time into a raised, thickened plaque on the lower leg from long-term licking. [1] See hot spots on dogs.
Is a lick granuloma caused by boredom or anxiety?
It can have a behavioral part, but medical causes such as allergies, joint pain, infections, mites and tumors are also possible, and some lesions that look like lick granulomas turn out to be other diseases. [1][3]
Why do lick granulomas keep coming back?
Infection deep in the lesion can keep the itch-lick cycle going, and surface tests often miss it. [1][4] The vet review says the underlying cause, the infection and any behavioral part all need attention together. [1]
Can I put a bandage on it?
Ask your vet. Stopping the licking helps healing, but the right method depends on the lesion and your dog.
The bottom line
A lick granuloma is a sign that something keeps your dog licking: itch, pain, infection, anxiety, or a mix. Successful treatment usually means tackling all of them together, guided by your vet, rather than just covering the sore.
This article is for general information and is not a substitute for veterinary advice. If your dog keeps licking one spot, please see your veterinarian.
Sources
- Shumaker AK. Diagnosis and Treatment of Canine Acral Lick Dermatitis. Vet Clin North Am Small Anim Pract. 2019;49(1):105-123. PMID 30268424. https://pubmed.ncbi.nlm.nih.gov/30268424/
- d’Angelo D, Sacchettino L, Carpentieri R, Avallone L, Gatta C, Napolitano F. An Interdisciplinary Approach for Compulsive Behavior in Dogs: A Case Report. Front Vet Sci. 2022;9:801636. PMC8988433 (CC BY). https://pmc.ncbi.nlm.nih.gov/articles/PMC8988433/
- Denerolle P, White SD, Taylor TS, Vandenabeele SI. Organic diseases mimicking acral lick dermatitis in six dogs. J Am Anim Hosp Assoc. 2007;43(4):215-20. PMID 17615402. https://pubmed.ncbi.nlm.nih.gov/17615402/
- Shumaker AK, Angus JC, Coyner KS, Loeffler DG, Rankin SC, Lewis TP. Microbiological and histopathological features of canine acral lick dermatitis. Vet Dermatol. 2008;19(5):288-98. PMID 18699812. https://pubmed.ncbi.nlm.nih.gov/18699812/
- Schnedeker AH, Cole LK, Diaz SF, et al. Is low-level laser therapy useful as an adjunctive treatment for canine acral lick dermatitis? A randomized, double-blinded, sham-controlled study. Vet Dermatol. 2021;32(2):148-e35. PMID 33471429. https://pubmed.ncbi.nlm.nih.gov/33471429/