Diagnostic criteria for carbaryl poisoning in sheep.

Sheep were used to study the effect of carbaryl in liver, heart, and brain and on cholinesterase activity. Carbaryl residues greater than or equal to 0.01 ppm in the brain were present in all sheep dying after dosing. Sheep dying acutely had higher levels of carbaryl and greater than or equal to 50% inhibition of brain cholinesterase activity, while sheep with prolonged death had lower carbaryl levels and less cholinesterase inhibition. Prolonged deaths were associated with pulmonary embarrassment, enteritis, hyperthermia, and metabolic acidosis. Carbaryl was rapidly degraded in stored blood samples but was stable in dead brain tissue.