Types of Canine Lupus, Symptoms, and Treatments

Lupus is an autoimmune disease, meaning it occurs because the dog's immune system attacks its own body. Since it doesn't always happen the same way, we find two presentations of the disease.

In this article, we'll describe the symptoms of lupus, as well as the characteristics of the forms this condition can take in dogs. It's also very important to know that treatment is available.

What Is Lupus?

Lupus is a disease of autoimmune origin caused by the deposit of what are known as immune complexes in the epidermis, the outermost layer of skin, or in different organs.

Immune complexes are compounds formed by the binding of antibodies, proteins whose job is to recognize pathogens, and antigens, the name given to substances foreign to the body that trigger the immune response.

So, these complexes are part of the immune system's normal reaction, but when they build up, as in lupus, they cause disease. They cause cellular and vascular damage wherever they deposit.

What Causes Lupus in a Dog?

Predisposing factors include ultraviolet rays, some vaccines made with modified live viruses, and genetic causes, but the exact trigger causing the immune system's reaction is unknown. Because of this, we also can't take preventive measures.

Certain breeds are considered to have a higher predisposition to this disease. The Collie, German Shepherd, and Husky more often suffer from discoid lupus erythematosus.

Symptoms of Lupus in a Dog

The clinical picture a dog with lupus will develop depends on whether it has the systemic or cutaneous presentation of the disease. Either way, the appearance of signs such as the following should make us seek veterinary care:

• Lesions such as wounds and scabs on the face, ear flaps, paws, or genitals. The location varies depending on whether it's systemic or discoid lupus.
• Thickened paw pads that can ulcerate and even peel off.
• Itching.
• Pain.
• Polyarthritis, meaning painful inflammation in several joints, which we might notice as limping that shifts from joint to joint.
• Intermittent fever.
• Glomerulonephritis, a disease affecting the glomeruli, the filtering units of the kidneys.
• Anemia.
• Ulcerative stomatitis, causing mouth ulcers.
• Paronychia, an infection in the skin around the nails.
• Onychomadesis, meaning nails falling off.

Discoid or Cutaneous Lupus Erythematosus

This is a fairly common, benign form of lupus that only affects the skin, specifically the face. It usually starts with a small lesion on the nose/nasal plane where the skin has lost color, or, on the contrary, is reddened. This first lesion progresses into wounds and, once dry, scabs.

We may notice the lesions get worse when the dog is in sunlight. Considering all this information, the vet can reach a diagnosis of lupus, since the location of the lesions gives a good clue. Treatment includes oral and topical corticosteroids, vitamins, immunosuppressants, and antibiotics.

Systemic Lupus Erythematosus

In this presentation, the autoimmune disorder is multisystemic, meaning it affects different organs. Because of this, its clinical picture can be very different in each dog, which complicates and can delay diagnosis. In some cases, though, the symptoms point toward lupus, which will be confirmed with lab tests.

Besides the skin, the kidneys, heart, and joints are usually affected. Limping or an unusual gait often appears as the first symptom. The vet will request blood and urine tests and testing for antinuclear antibodies (ANA), which confirm the presence of an autoimmune disease.

ANAs are produced when the immune system can't properly tell apart its own elements from foreign ones, which is precisely what happens in lupus. For treatment, the vet will prescribe systemic immunosuppressants in an attempt to slow the immune system's reaction.

Can Canine Lupus Be Cured?

This disease, as we've seen, can be treated, but the prognosis will depend on which type of lupus the dog has. In the systemic case, it will be guarded, especially long-term. On the other hand, discoid lupus can usually be treated successfully.

Keep in mind that treatment for this disease can last for life. Generally, high drug doses are used at the start. These will gradually be reduced to find the lowest dose possible that keeps the dog with a good quality of life but with fewer side effects.

In addition, we'll prevent the dog from licking off topical medications, if applicable, and we need to protect it from the sun. For this, we can use topical products the vet will recommend. Exposure to ultraviolet light considerably worsens the clinical picture.

Bibliography Carlson and Giffin (2002): Manual práctico de veterinaria canina. Madrid: Editorial el Drac. Website of veterinary dermatologist Juan Rejas: http://dermatologiaveterinaria.unileon.es/