TOXICOPATHOLOGY OF OIL-FIELD POISONING IN CATTLE - A REVIEW

The toxicologic pathology of petroleum and oilfield-related chemicals is reviewed, and a field guide for toxicopathologic evaluation of catt le is given. Cattle will voluntarily Ingest petroleum and chemicals us ed in the exploration, production and transportation of crude petroleu m. Variability In chemical composition of petroleum from different fie lds will alter the type and severity of lesions observed. When airborn e pollutants are present, cattle are continually exposed and make exce llent sentinel animals. The lung, kidney, liver, gastrointestinal trac t, heart and brain are target organs for petroleum hydrocarbons. Expos ure to elemental sulfur can produce pulmonary pathology. Sulfur-contai ning gases are irritating to the mucosa of the eye and respiratory tra ct. Arsenic and lead cause lesions in the gastrointestinal tract, brai n, liver and kidney. Glycols are hepato-, nephro- and neurotoxic, and oral exposure to diethylene glycol produces corneal lesions. Invert dr illing fluids are fetotoxic. Nonpesticide organophosphate esters targe t the peripheral and central nervous systems. Toxicopathy is a strateg ic tool in the diagnosis of intoxications occurring in cattle after ex posure to oilfield chemicals. Cattle are sensitive to oilfield polluta nts and are a useful biomonitoring species.