Canine acral lick dermatitis (ALD), or lick granuloma, is a serious self-injury to a dog’s skin caused by obsessive licking (“Acral” pertains to or affects a limb or other extremity). Persistent licking causes the skin to become inflamed and over time it thickens. The area can’t heal because of the constant licking; also, the licking and inflammation cause itching, which causes more licking, which creates a vicious cycle of itching and licking. Secondary problems that can result from ALD are bacterial infection, ruptured hair follicles (a condition called furunculosis), and ruptured apocrine glands (a type of sweat gland in dogs). Any of these secondary conditions can make the itching worse and perpetuate the itch-lick cycle.
The most common spot for ALD is the front side of a forelimb, somewhere between the toes and the elbow. Acral lick dermatitis is most commonly seen in large breed dogs.