RESUMO
Ten of 40 cows died within 48 h of gaining access to a barn in which various chemicals were stored. Some of the surviving cows exhibited drooling, muscle tremors, and agitation. Postmortem examinations of 2 cows were performed in the field, and revealed nonspecific, moderate-to-severe pulmonary congestion. Liver and rumen contents, each from a different cow, were analyzed using a qualitative, multi-residue GC-MS method validated for the detection of pesticides and other chemical analytes. Using this method, extracts from the liver and rumen content samples were compared to atrazine (neat standard) and matrix-matched, control samples fortified with atrazine. GC-MS analysis detected atrazine at 215 m/z (NIST match >97%) with a retention time of ~13 min in liver and rumen content samples from our case. Detection of atrazine in the samples from the cows in this herd, combined with the clinical history, indicate that atrazine toxicity was the likely cause of clinical signs and death observed in this herd.