Pemphigus in Dogs

What causes pemphigus in dogs?

Pemphigus can be caused by factors internally or inside a dog’s body, externally or outside a dog’s body, and unexplained, also known as idiopathic.

Internal factors that cause pemphigus include particular breeds, genetic predisposition, abnormal or defective immune system, underlying medical conditions such as chronic skin allergies, or cancer.

External factors that cause pemphigus include overactive immune response, viral infections, ultraviolet (UV) light exposure, and drug reactions such as an allergic reaction to a particular medication or by causing changes in a dog’s immune system.

If, after extensive testing, no internal or external reason can be found, many cases are diagnosed as idiopathic pemphigus. This means that no underlying cause can be found. Such cases are frustrating for both owners and veterinarians.

Symptoms of Pemphigus in Dogs

Dogs often have a sudden onset of symptoms, appearing within a few days to a week, that affect the head, face, and ears, but can eventually involve the nose and also the paw pads. Specifically, mucocutaneous areas such as the lip, eyes, vulva/prepuce, and rectum will be affected.

Symptoms of Pemphigus Foliaceus (PF)

This is the most common autoimmune skin disease in dogs and cats, often seen in middle-aged and senior pets. Signs include loss of hair, scabs, and open sores around the head, face, and ears which over time can spread to other parts of the body. It is seen most often in Chow Chows, Akitas, Cocker Spaniels, Labrador Retrievers, Dachshunds, and English Bulldogs, however, it has been diagnosed in other breeds as well.

Symptoms of Pemphigus Erythematosus (PE)

This type of pemphigus looks very much like pemphigus foliaceus, although symptoms are usually less severe in appearance. German Shepherds, Collies, and Shetland Sheepdogs make up the predisposed breeds.

Symptoms of Pemphigus Vulgaris (PV)

This form of pemphigus in dogs attacks and penetrates the deepest layers of the skin, causing the most severe lesions to form. These are fluid-filled blisters, known as vesicles. These blisters often burst open causing painful open wounds. Blisters are usually seen at the edges of the lips and eyes but with time will usually spread to other areas of the body.

Diagnosing Pemphigus in Dogs

Diagnosing a dog with pemphigus includes a complete physical exam by a vet, blood work, and other recommended testing to rule out other diseases including bacterial or fungal skin infections and skin allergies. To accurately diagnose pemphigus requires a surgical skin biopsy.

Under anesthesia (in some cases your vet will opt to use local anesthesia while in others they may opt for general anesthesia) your vet, using a biopsy punch, will remove a small, circular sample of skin from an affected area. The skin sample will be sent to a laboratory where a veterinary pathologist will analyze it and examine it microscopically to determine a diagnosis.

The pathologist will send a completed report to your vet who will contact you with the results and set up a follow-up consultation to discuss treatment options and prognosis.

Treatment Options for Dogs with Pemphigus

Treatment options for pemphigus involve suppression of the immune system. These medications include corticosteroids (like prednisone), azathioprine, chlorambucil, or cyclosporine. Your vet will discuss the recommended medication including the side effects that you can expect, as well as important and frequent follow-up visits. This may include blood work to monitor your dog’s immune system and body organs that can be affected by the medications prescribed.

Dogs diagnosed with pemphigus need long-term, sometimes lifelong, therapy to manage the symptoms of pemphigus. Treatment goals include response to medication and using the lowest effective dose of medication that keeps your dog’s symptoms in remission without causing other problems due to the negative side effects from the medications.

In some cases, after many months, treatment may be slowly decreased and eventually stopped once symptoms are cleared and the dog is declared to be in remission by their vet. Pemphigus takes time to treat and improve, requiring owners to be patient and not become discouraged when their dog doesn’t improve quickly.

My dog has pemphigus. Will she get better?

PE carries a good prognosis for recovery with treatment. PF carries a good to guarded prognosis for recovery with treatment as the symptoms often come and go even when treated aggressively. Unfortunately, PV carries a poor prognosis for recovery and is often fatal as the clinical symptoms are more widespread.

The skin symptoms in many cases of pemphigus can usually be managed with medication, however, the side effects of the immune-suppressive medications often cause the worst effects on the dog.

Follow-up visits become an expensive challenge and side effects from medication affect a dog’s quality of life, leading to over 50% of dogs diagnosed with pemphigus to be euthanized.

When to Contact a Vet

If you notice your dog suddenly develops changes in their skin as described above, schedule an appointment with your vet to determine a diagnosis and treatment plan.

Read more:

Allergy Tests for Dogs

Common Myths About Allergies in Dogs

Common Skin Parasites in Dogs

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