Neonatal isoerythrolysis is a isease found in kittens and foals. It occurs when the mother has antibodies against the blood type of the newborn. During the first 24 hours of the neonate's life its gut absorbs all of the mother's antibodies that are passed in colostrum. Kittens and foals obtain the majority of their immune response from the colostrum. They are not born with a strong immune response. When they absorb the mother's antibodies against their blood type it causes lysis of the red blood cells leading to anemia. Symptoms include lethargy, pale mucus membranes, and blood in the urine. In the kitten this is referred to as fading kitten syndrome.