ABSTRACT
During 1977, 4,976 oil and gas wells were drilled in Oklahoma to an average depth of 4,892 feet. There were 2,253 successful oil wells and 1092 successful gas wells (26). The Oklahoma Animal Disease Diagnostic Laboratory investigated several cases where livestock in close proximity to drilling sites became ill or die. The case histories emphasize the need for a careful and complete diagnostic work-up. The identification and quantification of petroleum hydrocarbons, toxic chemicals and heavy metals in intestinal contents and tissues are diagnostically significant. The most difficult cases involve chronically ill and poor-doing animals following exposure to oil field wastes. The potential for litigation exists whenever cattle in close proximity to drilling and production sites become ill or die. Many of these cases could be prevented if livestock were prevented access to such sites by fencing or other means. The circumstantial evidence in many cases suggests the need for additional research on the toxicity of petroleum hydrocarbons, drilling muds and other oil dield wastes. Improves diagnostic methods should benefit both the livestock and oil industries.
