What Causes Canine Lupus?

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Uncommon in dogs, lupus erythematosus is a complex and potentially serious autoimmune condition. The rarer, more serious version can cause a dog's body to create antibodies against itself. The milder version affects the dog's skin. If Duke's been diagnosed with lupus, you'll never know the cause -- canine lupus is idiopathic -- but he can be treated.

Systemic Lupus Erythematosus

Systemic lupus erythematosus, or SLE, affects multiple systems in Duke's body. It is the most serious of the two types of lupus affecting dogs; the dog's body creates antibodies that attack his own blood, muscles, nervous system and other systems in his body. It can present anywhere, but is most common in the skin, kidneys, lungs, heart, liver and joints. Symptoms include lethargy, weakness, depression, lameness, swollen and painful joints, a stiff gait and thickened foot pads. Other signs of SLE include blisters and sores, mouth ulcers, swollen lymph nodes, seizures, protein in the urine and lower platelet and white blood cell count. Because other conditions mimic SLE symptoms and the symptoms can come and go, it can be difficult to diagnose. Diagnosis requires positive blood tests for specific antibodies combined with at least two of the most common symptoms.


Discoid Lupus Erythematosus

As with SLE, discoid lupus erythematosus, or DLE, is a case of Duke's immune system attacking the body. DLE is more common and affects Duke's face, specifically the bridge of his nose, lips, mouth and ears, and occasionally his feet, genitals and skin around his eyes. Aside from hair loss or skin sores or scaling in the affected areas, a dog with DLE is basically healthy. If Duke spends time in the sun and has DLE, his symptoms will worsen. DLE can strike when a dog's immune system isn't functioning properly; occasionally, a dog with DLE will go into spontaneous remission. This type of lupus usually requires a biopsy for diagnosis.


Causes of Lupus

There are a number of suspects for the cause of lupus, but the precise cause of the disease isn't known. For both forms, genetics are considered to be a key factor in triggering the condition, but the method of transmission is unknown. Certain breeds of dogs are affected by lupus more than others, and include beagles, Irish setters, Afghan hounds, German shepherds, rough collies, poodles, old English sheepdogs, malamutes, chow chows, Siberian huskies and Shetland sheepdogs. Though the disease affects few dogs, canine lupus is subject to rigorous research in the scientific community. Fortunately, more is known about the treatment of lupus.


Prevention and Treatment

Since the exact cause of lupus has not been determined, there's no way to prevent it. Dogs diagnosed with lupus should not be bred; if Duke's one of the more susceptible breeds, he'll do well with extra protection, such as using waterproof, high-level sunblock on the bridge of his nose and staying out of direct sunlight. If he's been diagnosed with DLE, he'll probably get a low dose of a glucocorticoid such as prednisone, as well as nutritional supplements. SLE treatment depends on the organs affected and often includes high doses of glucocorticoids and other drugs. DLE is rarely life-threatening and a dog with that sort of lupus frequently goes into remission, so the prognosis is good, though Duke may not be quite as handsome as he used to be. Unfortunately, SLE has a lower expectation of recovery, because it's unpredictable and debilitating to the dog.


By Betty Lewis

VetStreet: Lupus Erythematosus in Dogs
Veterinary Partner: Systemic Lupus Erythematosus (SLE)
University of Prince Edward Island: Lupus Erythematosus
Pet Wave: Lupus in Dogs
eCommons@Cornell: Systemic Lupus Erythematosus in a Dog : Diagnosis and Treatment

About the Author
Betty Lewis has been writing professionally since 2000, specializing in animal care and issues, business analysis and homeland security. Lewis holds a bachelor's degree in journalism from West Virginia University as well as master's degrees from Old Dominion University and Tulane University.