Skin Disease Caused by Licking in Dogs

Although acral lick dermatitis is not a life-threatening disorder, it can cause infection of the lesions, leading to more cause for licking, which will then create more lesions. There are two types of acral lick dermatitis, but it is sometimes impossible to tell which one your dog is suffering from. The most common type is behavioral acral lick dermatitis, which is caused by a psychological problem (i.e. anxiety, stress, boredom, fear, or obsessive-compulsive disorder). The physical type of acral lick dermatitis is less common and is caused by injury, infection (i.e. fungal or bacterial), allergy, or some kinds of joint diseases. Sometimes, a dog uses licking and chewing itself to release the stress or fear they are feeling. Some medical professionals speculate that the licking triggers the brain to release endorphins, which are natural chemicals that produce a good feeling.

Skin disease caused by licking (acral lick dermatitis) is a self-inflicted injury caused by dogs with a repetitive licking behavior, sometimes known as lick granuloma. While any size and breed of dog can have acral lick dermatitis in any spot of their body, it is more common in large breed dogs on the leg, foot, or elbow. This disorder is thought to be a behavioral problem caused by stress or boredom. The excessive licking of the skin causes sores and lesions that can get infected and turn into abscesses, which may produce bald spots.

Quite often, you may not observe any symptoms until the licking has caused lesions that are easily noticed. Many dog owners just ignore the licking because it is common for dogs to lick themselves and most owners do not see them doing it all the time. Some of the symptoms you may notice are:

• Excessive licking
• Chewing the skin
• Scratching constantly
• Weeping sores
• Abscesses on legs
• Bald spots
• Lesions from one millimeter to covering the entire leg

 Types

• Behavioral Acral Lick Dermatitis (most common) is caused by a psychological problem such as boredom, fear, stress, anxiety, or obsessive-compulsive disorder
• Physical Acral Lick Dermatitis (less common) is from an injury, allergy, joint diseases, fungal infection, or bacterial infection

There are multiple reasons for both physical and behavioral acral lick dermatitis. The most common reasons for each of these types are:

Behavioral Acral Lick Dermatitis

• Anxiety
• Boredom
• Fear
• Stress
• Obsessive Compulsive Disorder

Physical Acral Lick Dermatitis

• Injury
• Infection
• Allergy
• Joint diseases (i.e. arthritis)

In addition, certain breeds of dogs are more susceptible to acral lick dermatitis. The breeds most affected are:

• American Staffordshire Terriers
• Border Collies
• Boxers
• Dalmatians
• Dobermans
• English Setters
• English Springer Spaniels
• German Shepherds
• Golden Retrievers
• Gordon Setters
• Great Danes
• Irish Red and White Setters
• Irish Setters
• Labrador Retrievers
• Newfoundlands
• Pomeranians
• Pit Bull Terriers
• Staffordshire Bull Terriers
• Siberian Huskies
• Weimaraners

To get a definitive diagnosis of acral lick dermatitis, other illnesses have to be ruled out. Some of those illnesses are fungal infections, bacterial infections, mast cell tumors, and pressure sores. It is essential to give the veterinarian your dog’s complete medical history, including any recent illnesses and injuries, vaccination records, changes in behavior, and if your dog has been in contact with any other sick animals recently. The veterinarian will also need to know if there have been any recent changes in your dog’s life that could affect his mental health because acral lick dermatitis can be caused by a psychological disorder.

The veterinarian will do a comprehensive physical examination, which includes weight, blood pressure, heart rate, and body temperature. Some tests will also have to be done, such as urinalysis, blood gas, blood chemistry panel, complete blood count (CBC), glucose test, fungal and bacterial swabs and cultures, radiographs, allergy tests, and possibly a skin biopsy.

Treating physical acral lick dermatitis is much easier than the behavioral type because once the underlying physical disorder is treated, the dermatitis should go away. Behavioral acral lick dermatitis is much more difficult because by the time the disorder is noticed it has become an automatic response to certain stimuli, such as nervousness or fear of any kind. It can also be triggered by having too much energy and not getting enough exercise. Once your dog has started this behavior, it takes a lot of time and effort on your behalf to help break the habit. The most important part of treatment is treating the lesions so they do not become infected. Antibiotics (i.e. ampicillin), corticosteroids (i.e. prednisone), and antihistamines (i.e. Benadryl) are helpful in treating most lesions even if they are infected.

Some antidepressants like selective serotonin reuptake inhibitor medication (i.e. Prozac) has been found to be effective in two thirds of those with behavioral acral lick dermatitis.

It is essential that your dog gets plenty of exercise, both physical and mental. Just letting your dog out in the yard once or twice a day is not enough. You have to be able to provide mental stimulation for your dog as well, so interaction with you is important. Obedience classes may also be helpful as will sports or a trip to the dog park a few times a week. Having a dog is a big responsibility and you have to spend time with your dog on a daily basis. Be sure to follow up with your veterinarian and continue to keep regular annual appointments.