Epidermolysis Bullosa in Dogs

Epidermolysis bullosa is caused by a mutation in the collagen gene which results in a lack of collagen in the skin. This disfiguring condition may be seen at birth or within the first few weeks of life. In many cases, affected puppies may not live past three months of age.

The two most serious types of epidermolysis bullosa include the basement membrane zone, which is the most important part of the skin’s structure because it basically holds the skin to the other structures of the body, such as the muscles and bones. Without this structure, the skin is torn away from the body, leaving muscle and other tissue exposed and this usually leads to further damage and infections. This layer is also the source of regulating the transfer of nutrients to the connective tissues.

Epidermolysis bullosa is a hereditary autoimmune skin disorder in dogs that includes several forms:

• dystrophic epidermolysis bullosa
• junctional epidermolysis bullosa
• and epidermolysis bullosa simplex
  

These are classified by the location of the blistered areas and layers of skin affected. The main effect of epidermolysis bullosa is the blisters and ulcers in certain areas such as the mouth, ears, genital area, back, face, and footpads.

This disorder causes severe breakdown of the dermal and epidermal structure with the slightest trauma to the skin. The separation of these two structures creates blisters that burst, leaving large areas of painful erosive lesions. The first type of epidermolysis bullosa (simplex) is severe and may be fatal if not treated. The second two types (junctional and dystrophic) are usually fatal even with treatment.

The symptoms of epidermolysis bullosa depend on which type your dog has, but it always includes blistering and ulcerations in areas of the most friction or trauma.

Epidermolysis Bullosa Simplex

• Fluid-filled blisters anywhere on the body but usually in areas most susceptible to trauma
• Raw skin in areas of trauma such as feet, elbows, face, hips, knees, back, groin, and ears

Junctional and Dystrophic Epidermolysis

• Lesions and bleeding in the mouth and upper digestive system
• Blistering in the throat which may cause breathing trouble
• Skin tears away from body from the slightest pressure
• Inability to walk due to footpad blistering
• Severe blistering and raw skin all over the body
• Besides skin issues, your puppy may show signs of listlessness and depression due to pain and weakness

Types

• Epidermolysis bullosa simplex is the least severe of the group, only affecting the basal cell layer
• Junctional epidermolysis bullosa includes the lower layer (basement membrane) and is usually fatal
• Dystrophic epidermolysis bullosa goes below the basement membrane into the subepidermal area and is almost always fatal

• Epidermolysis bullosa simplex most often occurs in Shetland Sheepdogs and Collies
• Junctional epidermolysis bullosa is noted most often in mixed breed dogs, Shorthaired Pointers, Toy Poodles, and Beaucerons
• Dystrophic epidermolysis bullosa is most common in Akitas and Golden Retrievers

Your dog will need to be examined by a veterinary professional as soon as possible. Since this is a genetic condition, it will likely show up right away after birth or in your puppy’s first few months of life. The veterinarian will need to know your pet’s medical history and if he has had any immunizations yet. Also, you should mention any other symptoms you have noticed besides the obvious skin issues such as lack of appetite or weakness. A detailed physical examination will be done, which usually includes a complete health assessment with vital signs, and the veterinarian will palpate your puppy carefully to prevent skin trauma. The veterinarian will be looking for abnormal behavior and physical characteristics as well. The most accurate way to get a definitive diagnosis is with immunohistochemistry using an IgG light and blood tests.

A chemical profile, complete blood count and culture, and urinalysis will be done to eliminate other causes of skin problems. The IgG test will likely show major reactivity of the epidermal junction and an immunofluorescence test (IIF) should reveal BMZ proteins. Some veterinarians may decide to perform an ultrasound and x-rays, but these must be done carefully due to the delicacy of the skin and lack of protection of the underlying muscle.

Although there is no treatment that can cure the disorder, epidermolysis bullosa simplex can be controlled with steroids, prednisone, corticosteroids, and other immunosuppressive drugs. Also, with all three types of epidermolysis bullosa there are ways to alter your dog’s environment to reduce trauma to skin and lessen the symptoms.

Drugs

Oral prednisone, leflunomide steroids, cyclosporine, mycophenolate mofetil (MMF), and azathioprine are all good choices for helping to slow down the disease.

Environmental Changes

To reduce injuries to the skin, your dog’s environment should be changed to keep your pet from hurting himself. Many dogs are unable to get up and move around so this adjustment is not always needed.

Unfortunately, the prognosis is grave for dogs with dystrophic epidermolysis bullosa and junctional epidermolysis bullosa because these are almost always fatal, even with treatment. However, epidermolysis simplex is controllable with medication and preventive care, as well as regular visits to see the veterinarian.