Lead arsenate poisoning in a herd of beef cattle.

Lead arsenate poisoning was diagnosed in 2 beef heifers and was suspected in 6 other cattle from the same herd that had died previously and were not examined. Clinical signs in affected cattle included staggering, dehydration, hemorrhage, acidemia, and shock. Diagnosis was by arsenic and lead analysis of urine samples and kidney and liver tissue digests. Both examined heifers died within 4 days of onset of clinical signs. These cattle had been moved from an area with poor grazing conditions to a pasture with abundant forage. This pasture had an open shed that contained an open sack of lead arsenate insecticide. Old stores of this inorganic insecticide may still exist on farms or ranches, and are a hazard to livestock.