The value of zinc protoporphyrin in equine lead poisoning: a case report.Vet Hum Toxicol. 1981 Feb; 23(1):12-5.VH
A diagnosis of lead poisoning in a foal was established based on clinical signs and the presence of an elevation in the concentration of blood lead (40 microgram/dl). Additionally, ZPP was determined in whole blood and found to be significantly elevated compared to 10 normal horses not exposed to lead (634 vs 73 microgram/dl). An elevation in ZPP in man has been found to be a sensitive biochemical indicator of lead toxicity even before overt clinical signs are present. This report suggests that ZPP may be a useful screening test for evaluating biological toxicity due to lead in horses and possibly other species.