Bullous Pemphigoid in Dogs

Bullous pemphigoid in dogs is an autoimmune skin disease which is identified by the large, clear fluid filled thin-walled sac (blister or cyst-like sacs) from which the term “bullous” emanates.   Vesicles (blisters) or ulcers can be identified in the mouth, at junctions of skin and mucous membranes, armpits and groin areas.  Often the dog will need to be hospitalized so that the blisters can be sampled and tested every couple of hours as bullous pemphigoid can resolve very quickly with repeat episodes very likely if not treated appropriately.

Bullous pemphigoid is a type of autoimmune skin disease which can occur in dogs, cats and humans.   It has been found to be a relatively rare disease in dogs and cats.

The name pemphigoid may suggest that it is a disease related to pemphigus, another family of autoimmune skin diseases, while it actually is a different type of autoimmune disease involving the skin.  Here are some of the symptoms which could present in your dog:

• Itching
• Large red welts
• Hives
• Blisters
• Ulcers

Types  

Bullous pemphigoid gets its name from the fact that the term “bullous” is a medical designation given to a “large thin-walled, clear fluid-filled sac” and, while not a great deal is known about the causes of the condition,  clinical, morphological and immunological studies seem to suggest there is an autoimmune component to its nature.  

There seems only to be one type of bullous pemphigoid while there are several types of pemphigus.  The difference between the two conditions appears to be basically in the depth of the structure and formation of the “blister”, with pemphigus forming in the intraepidermal (outermost layer of the skin) while the pemphigoid forms in the subepidermal (deeper layers) of the skin.

As noted above, bullous pemphigoid is similar only in name to another family of autoimmune diseases called pemphigus.  Bullous pemphigoid in dogs was first reported in 1978, being known as a human disease prior to this.  Scientific testing and research are ongoing to determine if there is a connection between that found in humans versus that found in canines.  This has not yet been positively established, as the disease in canines is fairly rare.  

In an autoimmune disorder, the body’s normal defense mechanism gets mixed up and literally attacks its own tissue, some of which are the defensive weapons designed to protect and fend off infective organisms.  This “mixup” in the immune response system results in the malfunctioning of the immune system, allowing various infective organisms the opportunity to wreak havoc in a variety of ways in the body of the host.  This sets the stage for any number of bacterial, fungal or parasitic organisms to invade your dog’s skin and other tissues, causing the blister of bullous pemphigoid to form.

Diagnosis of bullous pemphigoid in dogs can be complex in that the blister that forms in the subepidermal tissues, being thin-walled, can rupture and resolve before the clear fluid inside it can be biopsied and tested for the infective organism responsible for the condition.  The dog must pretty much be placed under hospital care as soon as the lesion is discovered so that it can be checked every couple of hours and specimens taken of the fluid inside the blister for laboratory evaluation.  When you note the blister, call your veterinary professional as soon as possible so that he can evaluate your dog.  Be sure to let him know how long the blister has been present as well as any of the other symptoms noted above and the duration of those symptoms.  

Your dog's medical history will be very helpful as the veterinarian works toward his diagnosis. He may be able to obtain a specimen for lab assessment at the initial visit and this may be enough to ascertain the identity of the organisms at the root of the blister.  However, be prepared for additional specimen gathering in the event that he is not able to get enough information initially.  As noted above, it may require the close observation and testing which will only be available if your dog is admitted as a patient.

Once the infective organism is identified, a treatment plan can be recommended and implemented.  Generally, bullous pemphigoid in dogs is treated using prednisolone with or without azathioprine or chlorambucil, or tetracycline and niacinamide or dapsone, depending on the organism found to be responsible for the infection.  Since this disease has an autoimmune component in its nature, you should expect that an effective treatment should require 3 to 8 weeks initially for maximum efficacy and then a maintenance dosage which will be required long term, potentially for the rest of the dog’s life.  

Because bullous pemphigoid is caused by an upset immunological system, this disease can continue to recur with poor long term prognosis if appropriate treatment is not given.   The long term prognosis is considered poor at best with this disease but it can be fatal more quickly if not appropriately treated and monitored.

Bullous pemphigoid in dogs is a disease of which little is known and this is mainly due to its rarity.  It is also a disease which will continue to recur since it is an autoimmune disorder for which there is no cure and for which the long term prognosis is considered poor.  Prompt medication attention with prompt diagnosis and treatment will go a long way toward easing the discomforts of this disease for your pet as well as for you and your family.  

This disease is not one which would benefit the breeding process as you would not want to pass this trait along to offspring, thereby destroying the purity of the breed.  But, the inability to breed your dog, whether male or female, will not prevent it from being loved and cared for by you and your family.  This disease condition will also not prevent your beloved pet from showing his love to each member of your family as well.