Autoimmune diseases occur when the immune system of an animal mistakenly attacks different cells in their own body, like red blood cells. A common autoimmune disease in dogs is immune-mediated hemolytic anemia (IMHA) where the red blood cells are targeted and destroyed. This syndrome is commonly fatal in dogs and new tests and treatments are needed. It is unknown what causes the syndrome in all dogs, but there is now evidence that bacteria that live in the intestines sometimes get in the blood stream and can trigger autoimmune diseases, including IMHA.