Lupus in Dogs

Lupus is an autoimmune disease, in which a dog’s immune system attacks the dog’s own cells and tissues. While lupus is divided into many types, cases fall into two basic categories: cutaneous lupus (which affects only the skin) and systemic lupus (which affects the entire body). In dogs, cutaneous lupus is more common than systemic lupus.

While the exact cause of lupus is unknown, a 2004 study showed that dogs living in a home with a human lupus patient are at higher risk of developing systemic lupus than dogs that do not live with someone who has lupus (1). This suggests that environmental or infectious factors may play a role in this condition.

What is Lupus?

In dogs with lupus, the immune system attacks the body’s own cells and tissues.

Normally, the immune system in dogs (like in humans) is responsible for protecting the body against disease. In this role, the immune system attacks bacterial, fungi, virus-infected cells, tumor cells, and other problematic cells within the body. 

In lupus, however, the immune system becomes misdirected. This leads it to attack cells and tissues within the body, causing a variety of harmful effects.

Types of Lupus in Dogs

There are several different types of lupus in dogs. These lupus types vary in their symptoms, appearance under the microscope, recommended treatment, and prognosis.

Most cases of lupus in dogs fall into the category of cutaneous lupus. These types of lupus affect the skin, causing inflammation and other lesions. 

Types of cutaneous lupus include: 

• Discoid lupus erythematosus (the most common cutaneous form of lupus and the most common form of lupus overall)
• Mucocutaneous lupus erythematosus
• Vesicular cutaneous lupus erythematosus
• Exfoliative cutaneous lupus erythematosus

Systemic lupus erythematosus, in contrast, affects the entire body. Dogs with systemic lupus may have skin lesions, but they also experience inflammation in other organs and tissues.

Symptoms of Lupus in Dogs

The symptoms of lupus in dogs can vary widely, depending on the type of lupus and progression of the disease. 

Symptoms associated with cutaneous lupus disease in dogs (which may also be observed with systemic lupus) include: 

• Loss of pigment on the nose (a previously-dark nose may turn pink)
• Loss of the normal cobblestone texture of the nose (the nose may feel smooth to the touch)
• Crusting of the nose
• Hair loss and/or crusting around the eyes and ears
• Widespread patches of hair loss and crusty skin
• Ulcers inside the mouth or on the lips

In dogs with systemic lupus, the following symptoms are often observed:

• Lethargy
• Decreased appetite
• Waxing and waning fever
• Joint swelling
• Episodes of lameness involving multiple legs or seeming to shift between legs

What Causes Lupus in Dogs?

The underlying cause of the immune dysfunction that causes lupus is unknown. 

Cutaneous forms of lupus, especially discoid lupus erythematosus, can be aggravated by sun exposure. In fact, discoid lupus erythematosus appears to be more common in sunny climates (2). 

Breeds that are predisposed to cutaneous lupus include Collies, German Shepherds, Shetland Sheepdogs, and Siberian Huskies. 

Systemic lupus is thought to have an underlying genetic cause, although sun exposure, exposure to certain drugs, and infectious agents may also play a role. 

Predisposed breeds include Afghan Hounds, Beagles, Collies, German Shepherds, Poodles, and Shetland Sheepdogs.

Diagnosing Lupus in Dogs

Discoid lupus and other cutaneous forms of lupus

Cutaneous lupus is typically diagnosed via a skin biopsy. Your veterinarian will obtain a biopsy sample of your dog’s affected skin. A biopsy punch may be used, to allow your veterinarian to remove a circular section of skin with minimal damage to surrounding tissues. Depending on your dog’s personality and the location of the biopsy, the sample may be collected under local anesthesia (a nerve block), mild sedation, or general anesthesia. 

After removing the biopsy specimen, your veterinarian will suture the wound closed. It is important to follow your veterinarian’s instructions on caring for the surgical wound. You may need to return to the veterinarian in 7-14 days for suture removal. 

Systemic lupus

Systemic lupus is more challenging to diagnose. Dogs often present with nonspecific signs, which could potentially be attributed to a number of different conditions. Therefore, a number of tests are often required to arrive at a diagnosis. 

Your veterinarian will probably start by performing screening blood work, including a complete blood cell count and a serum biochemistry. Affected dogs may have decreased numbers of red blood cells and platelets in their blood, in addition to increased or decreased numbers of white blood cells. Indicators of organ function may also be abnormal, depending on the organ system that is affected. 

If your dog has swelling in the joints, your veterinarian may perform a joint tap. Joint fluid analysis in dogs with systemic lupus typically shows significant numbers of inflammatory cells without evidence of infection.

The most specific test for systemic lupus is the antinuclear antibody (ANA) test. This blood test looks for antibodies that the immune system can make against materials in the nucleus (center) of animal cells. A positive ANA titer test in a dog with clinical signs and history suggestive of systemic lupus is adequate to make a diagnosis. 

False-positives and false-negatives do occur, however, and this test must be interpreted in light of a dog’s clinical appearance and history.  

Treatment for Lupus in Dogs

The goal of treating lupus is to suppress the body’s abnormal immune response. 

In some cases of cutaneous lupus, especially when skin lesions are confined to a single area (such as the nose), topical medications may be all that is needed for treatment. Your veterinarian may prescribe a topical cream ointment containing steroids or other immunosuppressive agents. Dogs with cutaneous lupus should also be kept out of the sun as much as possible. 

The overall prognosis for dogs with most forms of cutaneous lupus (with the exception of exfoliative lupus) is good. The condition often waxes and wanes throughout the remainder of the dog’s life, but can often be controlled with medication. If left untreated, however, lupus can progress to squamous cell carcinoma. 

In systemic lupus, or cases of cutaneous lupus with widespread lesions, oral medications are required. Your dog may be prescribed steroids or other immunosuppressive drugs to calm the immune system’s reaction. Dogs receiving these medications require regular blood work monitoring, so that side effects can be detected and addressed.

Dogs with systemic lupus have a guarded prognosis. Approximately 40 percent of dogs diagnosed with this condition are euthanized within the first year.* Dogs that respond to medications are continued on these medications long-term, with treatment protocols adjusted as needed when relapses occur. In dogs that show a favorable additional response to steroids, approximately 50 percent survive long-term.* 

Medications Used to Treat Lupus in Dogs

Medications used to treat cutaneous lupus include the following: 

Tacrolimus: This topical ointment is typically applied to lesions every 12-24 hours, or as directed by your veterinarian. Dogs typically tolerate this medication well, with few (if any) side effects.

Topical steroids (such as betamethasone or triamcinolone): Topical steroid ointments or sprays are also typically applied every 12-24 hours. Steroids are also typically well-tolerated, but may lead to thinning of the skin with long-term use. 

Tetracycline and niacinamide: These oral medications are often combined to help regulate the immune system. It may take several weeks to see a response.

Systemic medications used to treat systemic lupus (or severe or non-responsive cases of cutaneous lupus) include: 

Steroids (such as prednisone or prednisolone): Oral steroids are the primary treatment for systemic lupus and for challenging cases of cutaneous lupus. Side effects are common, however, and include increased thirst and urination, weight gain, skin and coat changes, and other secondary conditions. For this reason, steroids are typically tapered to the lowest effective dose for long-term maintenance.

Other immunosuppressive drugs (such as azathioprine, cyclosporine, mycophenolate): These medications may provide immunosuppressive benefits without the common side effects associated with steroids. Although these medications are more expensive and it may take experimentation to find the most effective medication for a particular dog, the decreased risk of side effects makes them an excellent option. 

Supplements including fatty acids may also be beneficial.

General Cost of Treatment for Lupus in Dogs 

The cost of diagnosing and treating lupus can vary significantly, depending on the type of lupus, the severity of the dog’s illness, and which medications are used for long-term treatment. Additionally, patient size influences cost significantly; larger dogs require larger drug dosages. 

In general, you can expect to spend the following:

• Initial diagnostics $250-$2,000
• Lifelong medication: $250-$1,000/year 
• Long-term blood work monitoring: $150-$1,000/year 

How to Prevent Lupus in Dogs

Discoid lupus, the most common form of lupus, is observed more commonly in dogs that receive significant sun exposure. Minimizing your dog’s sun exposure is the most effective method of preventing this condition.

There are no known measures to prevent systemic lupus in dogs. 

Related Conditions

• Pemphigus foliaceus 

* Hnilica KA. Autoimmune and Immune Mediated Skin Diseases. Presented at Atlantic Coast Veterinary Conference 2011.