Autoimmune Diseases in Dogs
The immune system is a marvelous machine operated by a strong regiment that has nothing to envy from the best task forces. While these special units composed by white blood cells, antibodies and other substances will normally fiercely fight against diseases and infections, at times something can go seriously wrong creating the grounds for the force to attack itself. These episodes of friendly fire are known as autoimmune diseases.
Autoimmune diseases in dogs are not very common but their incidence appears to be on the rise, concerning many breeders. owners and veterinarians. There are several different forms of such diseases that may affect various parts of the dog's body producing a variety of symptoms and disorders. Following are some of the most common autoimmune diseases affecting man's best friend.
Autoimmune Hemolytic Anemia
This form of anemia is caused by the immune system destroying red blood cells because they are erroneously marked as an enemy. These repeated attacks to the body's own red blood cell's ultimately cause anemia in the dog marked by the gradual onset of clinical signs such as lethargy, tiredness, pale gums and increased heart beats. In severe cases, dogs may exhibit jaundice and fever.
This autoimmune disorder is diagnosed with a complete blood count showing a low number of red blood cells. A Coomb's may further help confirm the diagnosis.
This autoimmune disorder occurs when the immune system erroneously destroys platelets, which play an important role for proper clotting blood. When this occurrence takes place dogs are prone to episodes of excessive bleeding after trauma or surgery, presence of purplish blotches under the skin suggesting spontaneous bruising ( known as ecchymosis) presence of pin-point bleeding (know as “petecchiae”) and presence of blood in the urine, in the stool or from the nose.
This autoimmune disorder is diagnosed through a complete blood count, a platelet count and a clotting profile. A bone marrow biopsy may be helpful as well.
Systemic Lupus Erythmatosus
The word systemic means ''the whole body'' therefore in the case of Systemic Lupus Erythmatosus, the immune system attacks several body tissues, bones, organs and tissues. This autoimmune disorder is also known as ''the great imitator'' because it is often confused with other conditions.
Affected dogs may develop polyarthritis, hemolytic anemia or thrombocytopenia, and other disorders. Affected dogs typically develop a high fever, lameness, lethargy or a symettrical dermatitis affecting the bridge of the nose. Diagnosis is obtained through a complete blood count, even though the antinuclear antibody test (ANA) is the definitive test for SLE.
Immune Mediated Polyarthritis
In this autoimmune condition, the immune system begins to erode the joints and bones. This form of autoimmune disorder will cause lameness that appears to shift from one leg to another, high fever, swelling and reluctance to move around.
Immune Mediated Skin Disease
Affected dogs develop autoimmune skin disease when the immune system attacks its own epidermal tissues. Dogs therefore will develop disorders such as Pemphigus foliaceous ,Pemphigus erythematosis and discoid lupus erythematosus . Affected dogs generally develop ulcerations, lesions, nail bed infections and oozing pustules.
Treatment of Autoimmune Disorders
Because autoimmune disorders are mainly caused by an exaggerated response from the immune system, immune suppressing medications are required to treat such conditions. The most commonly prescribed medications consist of steroids such as Prednisone. If steroids do not seem to work, more potent immunosuppressive drugs such as Cytoxan (cyclophosphamide) or Imuran (azathioprine) may be prescribed.