Retrospective study of cattle poisonings in California: recognition, diagnosis, and treatment

Anita Varga,¹ Birgit Puschner<sup>2

1</sup>William R Pritchard Veterinary Medical Teaching Hospital, Large Animal Clinic, School of Veterinary Medicine, University of California, Davis, CA, USA; ²Department of Molecular Biosciences and the California Animal Health and Food Safety Laboratory System, School of Veterinary Medicine, University of California, Davis, CA, USA

Abstract: In this retrospective study all suspect bovine intoxications submitted to the California Animal Health and Food Safety Laboratory between January 1, 2000 and December 31, 2011 were reviewed. A total of 1199 cases were submitted, but a diagnosis of intoxication was only established in 13.5% of cases. In these cases, overexposures to minerals, metals, and poisonous plants were determined as the most commonly diagnosed poisonings in cattle in California. Nitrate/nitrite poisoning was the most commonly diagnosed plant-associated intoxication, followed by gossypol and oleander. This study details the diagnostic challenges and treatment options for the most commonly diagnosed intoxications. To ensure proper treatment and prevention of new cases, accurate diagnosis is necessary, and therefore this review provides an essential tool for the food animal practitioner. Available toxicological analyses are offered at select laboratories, which can be time consuming and expensive, yet the potential for residues in consumed animal products and implications for human health necessitate testing and consultation. Any potential exposure to a toxicant in cattle should be reviewed to determine whether a residue hazard exists. Therapy focuses on immediate removal of the toxicant from the environment and from the gastrointestinal tract. With few antidotes available, most are cost prohibitive to treat numerous affected cattle. In addition, most antidotes will require extra-label drug use and establishment of meat and milk withdrawal times.

Keywords: toxins, toxicology, poisonous plants, bovine