It does not really give a clue as to whether the IMHA is due to a primary cause or if it is occurring for no apparent reason, though. The immune system wishes to attack this agent but manages to injure the rbc as well. Dogs with IMHA usually experience a sudden onset of clinical signs, including depression, lethargy, pale gums or conjunctiva, sometimes jaundice or a heart murmur and bruising. Vomiting or abdominal pain may be present. It is unusual for overt blood loss to occur, such as nose bleeds or excessive bleeding from a minor injury.
Death can occur rapidly, even with appropriate treatment.
Whenever hemolytic anemia is present it is wise to carefully rule out initiating causes that might be treatable. If any of these problems can be identified and treated the prognosis is much better. The combination of clinical signs and spherocytes on a blood smear give a strong indication of this condition very rapidly. It can be confirmed using a Coomb's test to check for antibodies adhered to red blood cells. A small percentage of dogs that have IMHA will not test positive on the Coomb's test.