Identification of cattle poisoning by Bifenthrin via earwax analysis by HS/GC–MS

The use of pyrethroids has increased over recent years, and corresponds to a higher exposure of animals to pesticide residues in the environment and diet. Here, an outbreak of pyrethroid poisoning in beef cattle was reported occurring in Midwestern Brazil. After veterinary evaluation, it was observed that the bovines presented common pyrethroid intoxication symptoms. Aiming to identify the cattle poising by pyrethroid, earwax samples were collected from two groups: exposed and nonexposed animals from the same farm. Blind earwax analyses of the bovines were carried out using headspace/gas chromatography–mass spectrometry (HS/GC–MS). The HS/GC–MS analysis detected the presence of bifenthrin in the earwax analysis of the exposed animals, confirmed by the comparison of its MS fragments with a bifenthrin standard, and also by its retention time relative to the internal standard. In summary, HS/GC–MS analysis of earwax emerges as a tool that can be used in the detection and monitoring of bifenthrin poisoning in cattle, as a useful veterinary diagnosis that ensures animal health and the safety of their products.