Primary or idiopathic AIHA
The dogs immune system is not working as it should and it makes antibodies that target and destroy its own red blood cells which deplete. The cause of the deficient immune system is not known. It is estimated that 75% of cases of AIHA in dogs are primary.
The surface of the red blood cells are altered by another disease or a toxin. Due to the alteration the dogs immune system does not recognise the cells and attack them as they are 'foreign' to the body. Secondary AIHA can be triggered by cancer, infection, drug reactions, Babesia (a parasite of the blood), snake bites, chemicals and even bee stings. In dogs cancer is the most common cause of secondary AIHA.