Most people have seen dogs scratching and biting themselves. Generally the assumption is that the dog has an itch. But sometimes the scratching and biting can become destructive, so that the dog actually injures himself. Excessive licking can start a cycle that is hard to break as the dog’s licking and biting leads to a lesion on his skin that gets infected. This in turn, causes the dog to lick even more, resulting in more hair loss and skin damage.
The causes of self-mutilation can stem from relatively common medical problems or psychological conditions. Allergies are a common reason dogs scratch and bite. Your dog could be allergic to food, fleas, or some element in his environment such as molds, dust, or grasses. Treating allergies can be a complex process and you should consult with your vet for specific advice. In general with allergies, you attempt to either avoid the allergen or manage the symptoms.
For example, if the dog has a food allergy and you can isolate the ingredient that causes the problem, you can switch to a food that doesn’t contain the ingredient. However, if your dog is allergic to dust or pollen, avoiding it can be difficult. In that case, your vet may recommend soothing shampoos, allergy shots, or other treatment to help manage the symptoms.
Hot spots or "acute moist dermatitis" are another problem that may cause intense itching. These red, inflamed areas are caused by a bacterial infection and can turn into a big problem as the dog causes further damage as he bites and scratches himself. Other skin infections, ear infections, or various parasites and mites can cause itching as well. For example, if you see your dog shaking his head and scratching at his ears a lot, it may indicate an ear infection. A trip to the vet is in order.
Not all licking and scratching has a medical cause however. Some cases of self mutilation actually are a form of obsessive-compulsive disorder. Just as people may become obsessive about washing their hands, dogs may become obsessive about licking or biting themselves.
For example, acral lick dermatitis is the term for a repetitive, compulsive licking disorder that leads to skin damage, infections, and lesions on the legs or feet. Other dogs may compulsively chase their tails to the point of biting and mutilating themselves. Or dogs will lick and suck their flanks until they have no hair.
These obsessive-compulsive behaviors may begin with a medical problem. The dog has a hot spot and starts licking his leg because it itches. But even after the hot spot is healed, he still licks his leg because the licking alleviates stress. Treating obsessive-compulsive disorders is challenging. Your vet may suggest an e-collar in the short term, prescribe anti-depressant medication, or enlist the help of a behaviorist.
No matter what the cause, if your dog is licking, biting, or chewing himself, there’s a problem. So talk to your vet about possible solutions. Being itchy or in pain is no fun for any dog.