Autoimmune Blood Disorders
When the immune system reacts against cells in the blood, your dog's life could be in danger. These threats may be acute and short term, or they may become chronic problems that require life-long care. These reactions may be triggered by drugs, vaccines, or viral infections, or the dogs involved may have a genetic predisposition.
Autoimmune Hemolytic Anemia
Autoimmune hemolytic anemia (AIHA) is a well-recognized syndrome that occurs when a dog's body no longer recognizes its own blood cells and attacks them. There are two versions of AIHA. The first is more rare and more serious. It generally involves middle-aged, larger-breed dogs. The disease comes on very quickly. The dogs show profound anemia, often have blood in their urine, and may appear yellow (jaundiced) on their light skin areas or by their eyes or gums. These dogs need immediate veterinary care, and the prognosis is not good.
The more common version of AIHA syndrome is acute but not quite so severe. In this case, signs may develop over a couple of days. Cocker spaniels have a genetic predisposition to developing this version of AIHA. Affected dogs become weak or fatigued easily. These dogs' gums will appear pale in color, and you may notice a yellowish cast to the gums and eyes. Astute families may notice that their dog's abdomen is a bit distended, as the liver and spleen are often enlarged. Luckily, dogs with acute AIHA generally respond well to therapy with corticosteroids such as prednisone that limit the body's immune responses.
Another autoimmune condition involving cells of the blood is autoimmune thrombocytopenia. Female dogs suffer from this syndrome more often than males. Thrombocytes are the cells that yield platelets, the components of blood that are so important in blood clotting. In this case, the cells that are attacked are the thrombocytes, so platelet numbers drop dramatically. Dogs with a very low platelet count develop reddish discolored areas on their skin. They may have nosebleeds, blood in the stool, and blood in their urine. Due to the bleeding, these dogs may become anemic as well! Dogs with autoimmune thrombocytopenia need treatment with corticosteroids and possibly immunosuppressive drugs as well. A blood transfusion may also be needed for short-term treatment. This should be done with typed blood that matches your dog's.
Dogs have different blood types, just as people do. DEA 1.1 is the most common type, occurring in 40 percent of all dogs. This is also the most reactive blood type, so dogs with DEA 1.1 positive blood should only donate to other DEA 1.1 positive dogs. Dogs with DEA 1.1 negative or DEA 1.2 negative blood are considered to be universal donors. Your veterinary clinic may keep donor dogs on call to help in emergencies.