Lupus Erythematosus in Dogs
The autoimmune disease lupus erythematosus is a great imitator, with a host of nonspecific signs that make it difficult to diagnose. Dogs are most at risk for the disease; it rarely occurs in cats. There are two forms: systemic lupus erythematosus (SLE), that can affect multiple systems within the body, and a milder form that is limited to the skin, discoid (or cutaneous) lupus erythematosus (DLE). Lameness, due to an inflammation of the joints or muscles, is the most common sign of the more serious form. Although skin lesions on the nose, face and ears can occur with both forms, the signs of DLE are typically limited to the skin. Both forms of lupus erythematosus are generally treated with immunosuppressive drugs.
Lupus erythematosus is an uncommon and complex autoimmune condition. Two versions of this disorder are seen in dogs, including systemic lupus erythematosus (SLE) and discoid (or cutaneous) lupus erythematosus (DLE). Although DLE is more common than SLE, it is thought to be a milder version of SLE.
In these diseases, the body creates antibodies against itself. In the case of SLE, these antibodies can attack any number of systems within the body, including joints, muscles, skin, kidneys, the nervous system, and the blood itself. Signs can vary widely, depending on the systems affected.
The condition is suspected to be hereditary, but the exact mode of genetic transmission is not known.
Symptoms and Identification
Lameness and fever are the most common signs associated with SLE, but many signs can be associated with it, depending on what organ systems the antibodies attack. Signs may also wax and wane, making diagnosis extremely elusive.
Signs of DLE may begin with a loss of pigmentation on the nose and lips, and progress to ulcerations and scarring on the face and ears. A skin biopsy is generally required for diagnosis.
A diagnosis of SLE can be offered if the patient 1) is positive on an ANA blood test for a specific kind of antibody and 2) has two or more of the following symptoms: skin lesions, oral ulcers, arthritis, inflammation of the covering of the heart (pericardium) or the lining of the chest cavity (pleura), kidney problems, neurologic symptoms and specific reductions in certain blood cells (platelets, red blood cells, or lymphocytes).
Lupus erythematosus runs in lines of dogs, most commonly in Collies, Shetland Sheepdogs, German Shepherds, Siberian Huskies, Malamutes, Afghan hounds, beagles and Chow Chows.
Treatment of DLE generally requires relatively low doses of glucocorticoids (like prednisone) along with simple nutritional supplements (like fatty acids). Use of sunblocks and avoidance of sun exposure is also recommended.
SLE is usually treated with high-dose glucocorticoids, and treatment efficacy is highly variable, depending on the organ systems involved. While some dogs respond very well to therapy, other dogs’ conditions are somewhat unresponsive to medical treatment. Chemotherapeutics and other immunomodulating drugs are often attempted, to no avail in some cases. Euthanasia due to uncontrollable symptoms or drug-related side effects is not uncommon.
Though inheritance modalities have not been established, it’s advisable to refrain from breeding affected dogs and their first-degree relatives (parents and siblings).
This article was reviewed by a Veterinarian.