These antibodies are then concentrated in the colostrum of the mare and passed on to the foal after birth. If the foal has inherited incompatible RBC antigens from the stallion and ingests colostrum containing antibodies directed against those antigens, NI may ensue. Mares may become sensitized by previous blood transfusion with blood of a similar type to the stallion or by transplacental RBC leakage during pregnancy. Foal born healthy, with onset of the desease between 6 - 96 hours of age. The diagnosis is based upon clinical signs and cross-match the mare and foal.
Treatment consists upon the severity of clinical signs.
If diagnosed before 24 hours of age, muzzle the foal, milk out the mare and feed the foal colostrum from another source. Blood transfusion will also be required at this point. The mares washed RBC's provide the best source. If this is impractical to accomplish, an aged gelding who has not had a blood transfusion is an alternative source. Other supportive care may be required, consult your vet.