The evaluation of earwax as a noninvasive specimen to determine livestock exposure to death camas (Zigadenus paniculatus)

Authors: Lee, Stephen; Stonecipher, Clinton - Clint; Welch, Kevin; Cook, Daniel

Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2024
Publication Date: 11/20/2024
Citation: Lee, S.T., Stonecipher, C.A., Welch, K.D., Cook, D. 2024. The evaluation of earwax as a noninvasive specimen to determine livestock exposure to death camas (Zigadenus paniculatus). Toxicon. 252: Article 108181. https://doi.org/10.1016/j.toxicon.2024.108181.
DOI: https://doi.org/10.1016/j.toxicon.2024.108181

Interpretive Summary: Foothill death camas (Z. paniculatus) grows on the foothill ranges of western North America and is acutely toxic to livestock grazing these ranges. The toxic alkaloids in foothill death camas are zygadenine and a series of zygadenine esters, with zygacine, the 3-acetyl ester of zygadenine, being the most abundant. In this study, earwax was evaluated as a specimen to determine livestock exposure to foothill death camas. Death camas alkaloids were detected in the earwax of sheep administered oral doses of foothill death camas alkaloids. In addition, death camas alkaloids were detected in the earwax of sheep that grazed rangeland with abundant death camas. This study demonstrates the potential of earwax as a noninvasive specimen for chemical analyses to aid in the diagnosis of livestock that may have been exposed to and poisoned by death camas. The results from this study indicate that diagnosticians should analyze for zygacine and zygadenine in the earwax of livestock suspected to have been poisoned by foothill death camas.

Technical Abstract: Foothill death camas (Z. paniculatus) grows on the foothill ranges of western North America and is acutely toxic to livestock grazing these ranges. The toxic alkaloids in foothill death camas are zygadenine and a series of zygadenine esters, with zygacine, the 3-acetyl ester of zygadenine, being the most abundant. In this study, earwax was evaluated as a specimen to determine livestock exposure to foothill death camas. Death camas alkaloids were detected in the earwax of sheep administered oral doses of foothill death camas alkaloids. In addition, death camas alkaloids were detected in the earwax of sheep that grazed rangeland with abundant death camas. This study demonstrates the potential of earwax as a noninvasive specimen for chemical analyses to aid in the diagnosis of livestock that may have been exposed to and poisoned by death camas. The results from this study indicate that diagnosticians should analyze for zygacine and zygadenine in the earwax of livestock suspected to have been poisoned by foothill death camas.