Systemic lupus erythematosus (SLE) is a fairly rare chronic and potentially-fatal autoimmune disease. It is an autoimmune disease that affects multiple systems. In SLE, the dog’s immune system fights itself by forming antibodies that “protect” it against its own cells and tissues. This results in inflammation and tissue damage in the skin, heart, lungs, kidneys, joints, nervous system, or blood. Usually several organs are affected.
SLE is one of the two forms of Lupus erythematosus – an uncommon and complex autoimmune condition. The other form is known as Discoid (or cutaneous) Lupus Erythematosus (DLE). While DLE is specific to skin disorders, SLE affects multiple organs in the body.
Some of the breeds that appear to have a predilection for SLE include Shetland sheepdogs, collies, German shepherds, old English sheepdogs, Afghan hounds, beagles, Irish setters, and poodles. The mean age is six years, but it can occur at any age. Gender does not play a role.
The clinical signs associated with SLE in dogs include :
Lethargy
Fever
Loss of appetite (Anorexia)
Musculoskeletal
Deposition of immune complexes in the synovial membranes (the soft tissue lining the surfaces within the joints)
Swollen and/or painful joints – major presenting sign in most patients
Shifting-leg lameness
Muscle pain or wasting
Skin/exocrine
Deposition of immune complexes in the skin
Skin lesions
Symmetric or focal skin lesions – redness, scaling, ulcers, depigmentation, and/or hair loss
Ulceration of mucocutaneous junctions and oral mucosa may develop – a region of skin comprising both mucosa and cutaneous skin; these mostly occur near the orifices of the body at which the external skin stops and the mucosa that covers the inside of the body starts (e.g., mouth, anus, nostrils)
Renal/urologic
Deposition of immune complexes in the kidney
Hepatosplenomegaly – enlargement of the kidney and the liver
Blood/lymph/immune system
Autoantibodies against erythrocytes, leukocytes, or platelets (red and white blood cells)
Lymphadenopathy – swollen lymph nodes
Other organ systems may be affected if there is deposition of immune complexes or antibodies, or when T cell-mediated cells (lymphocytes) attack
