Acral lick granulomas – which are also known as acral lick dermatitis – are skin lesions that are typically found on a dog’s lower limb or flank and are caused by excessive licking.
Acral lick granulomas are reddened, thickened, scarred and irritated skin. The constant licking causes the wound to become infected with bacteria.
What’s the primary cause that may compel a dog to excessively lick or suck at a spot?
Veterinarian Rod Rosychuk of Colorado State University states:
- A seasonal or environmental (atopic) allergen is usually the primary cause.
- He does not rule out a food sensitivity or intolerance as a possible primary cause.
- Uncommon or rare causes include trauma, bone or joint pain, a foreign body such as a pine needle, the feeling of pins and needles, mites, fungal infection, or behavioral issues such as anxiety.
Many veterinarians believe that behavioral issues are actually a more common cause. However, Dr. Rosychuk says that patients that develop acral lick granulomas due solely to behavioral issues generally exhibit additional behaviors such as phobias, tail chasing, circling, stress, obsessive-compulsive tendencies, separation anxiety or rhythmic barking. A common example is the flank sucking behavior of Doberman pinschers.
In fact, these behavioral issues can exacerbate (or perpetuate) a lick granuloma caused by something else such as an atopic sensitivity.
Think about it this way. Let’s say you get a pimple, and already exhibit obsessive-compulsive tendencies like constant handwashing. Now, the cause of the pimple is from excess sebum and dead skin cells getting trapped in the pores of the skin. However, you trying to pop the pimple before it turns white is a sign of obsessive-compulsive behavior. So, you might be prolonging the life of the pimple and could be causing a permanent scar.
In addition to behavioral issues, other perpetuating factors that could cause a dog to continuously lick and worsen a wound are deep bacterial infections and/or ruptured hair follicles.
Thus, acral lick granulomas are usually multi-factorial. Multi-factorial problems demand a multi-pronged approach.
Testing the deep tissue for bacterial infections.
Shumaker et al. found that the deep tissue usually contains different bacteria than the surface tissue. In their study, only eight out of 22 surface cultures correlated with the deep culture results.
Testing for the specific bacteria.
Shumaker and team found Staphylococcus spp. 60% of the time, followed by Pseudomonas spp. (8%) and Enterobacter spp. (8%). 50% of cases were multi-drug resistant and 25% were methicillin resistant.
Once this culture is completed, you can discuss if antibiotics will help with your veterinarian.
Treating the wound topically.
Dr. Karen Becker suggests treating the wound with betadine (povidone iodine) twice daily. She also lists several other topical remedies.
Breaking the “itch-lick” cycle.
You can attempt to break the” itch-lick” cycle with a deterrent such as a topical treatment, an e-collar, leggings or a bandage placed on another part of the body to divert the dog’s attention to lick there so the wound can heal. Many veterinarians do not think these methods work, but they still are worth a try. Note: One injection of a medium-acting corticosteroid under the lesion may be needed and is usually very effective in reducing the urge to itch and let the area heal.
Testing for food, seasonal and environmental sensitivities.
For food reactivities, we suggest our NutriScan Food Sensitivity and Intolerance Test that tests saliva (see http://www.nutriscan.org). For the others causes, we suggest blood/serum allergy or skin patch testing, although the latter can be unsightly.
Testing for hypothyroidism and thyroiditis.
An association has been established between aberrant behavior and thyroid dysfunction in the dog. Typical clinical signs include unprovoked aggression towards other animals and/or people, sudden onset of seizure disorder in adulthood, disorientation, moodiness, erratic temperament, periods of hyperactivity, hypoattentiveness, depression, fearfulness and phobias, anxiety, submissiveness, passivity, compulsiveness, and irritability.
Whether or not your dog is diagnosed with hypothyroidism or thyoiditis, you should try to get your dog out and about more because boredom caused by lack of interaction or long periods of confinement could be contributing to the lick cycle.
Veterinarians can prescribe antidepressants and antianxiety medications. However, these are generally undesirable, except in severe refractory cases.
Becker, Karen. “What Is Canine Acral Lick Dermatitis or Lick Granuloma?” Healthy Pets Mercola, 31 Aug. 2012, http://healthypets.mercola.com/sites/healthypets/archive/2012/08/31/dogs-lick-granuloma-disorder.aspx.
Dodds, Jean. “Aberrant Behavior and Thyroid Dysfunction in Dogs”. Hemopet, 11 Sept. 2013, https://www.hemopet.org/dog-aberrant-behavior-thyroid-dysfunction/.
Rosychuk, Rod. “Canine Lick Granuloma – World Small Animal Veterinary Association World Congress Proceedings, 2011”. VIN, 2011, https://www.vin.com/apputil/content/defaultadv1.aspx?pId=11343&id=5124321.
Shumaker, A.K., et al. “Microbiological and Histopathological Features of Canine Acral Lick Dermatitis.” Veterinary Dermatology, vol. 19, no. 5, Oct. 2008, pp. 288–298., doi:10.1111/j.1365-3164.2008.00693.x, https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-3164.2008.00693.x.