Heavy metal concentrations in injured racehorses.

Records were reviewed of horses that had fatal injuries at California racetracks over a 16-mo period. Horses were categorized based on injury type, sex, age and breed. Arsenic, cadmium, copper, iron, lead, molybdenum and zinc concentrations were measured in the liver and kidneys from each horse. Arsenic and lead were not detected in any tissues. Liver heavy metal concentrations were not related to the injury type. Kidney iron concentrations were significantly (P < 0.05) higher in horses with ligament ruptures and in horses with fractured sesamoid, carpus or metacarpus/metatarsus bones. Liver cadmium, kidney cadmium, and liver iron were higher (P < 0.05) in horses > 2 y old than in 2-y-olds. Liver cadmium concentrations were higher (P < 0.05) in Thoroughbreds than in Quarter Horses.