The traditional veterinary community considers GME to be idiopathic, which means we don’t know why it happens. However, there is also suspicion that the disease may be caused by an abnormal immune response to an infectious agent. While most conventional vets don’t acknowledge a link between autoimmune diseases and vaccines – especially Lyme, rabies, and leptospirosis vaccines – holistic vets have long voiced concern about what certainly seems to be a cause-and-effect relationship between certain vaccines and the subsequent development of autoimmune disorders in pets.