*The development of kernicterus. The increasingly elevated levels of bilirubin with in the bloodstream can cross the immature blood–brain barrier in the foal and result in chemical toxicity to the brain. The brain damage can be permanent and be represented by persistent seizures or maladjustment. | *The development of kernicterus. The increasingly elevated levels of bilirubin with in the bloodstream can cross the immature blood–brain barrier in the foal and result in chemical toxicity to the brain. The brain damage can be permanent and be represented by persistent seizures or maladjustment. |