ARS | Publication request: Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause

Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 13, 2010
Publication Date: January 2, 2011
Repository URL: http://dx.doi.org/10.1016/j.toxicon.2010.11.009
Citation: Panter, K.E., Gardner, D.R., Stegelmeier, B.L., Welch, K.D., Holstege, D. 2011. Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause. Toxicon. 57(1):157-61. DOI:10.1016/j.toxicon.2010.11.009

Interpretive Summary: Immature water hemlock seed heads were responsible for the death of 9 cows in central Utah. Chemical analysis of the hemlock seed heads determined that toxic compounds structurally similar to those found in the highly toxic roots/tubers were also present in the immature seed heads and were responsible for the poisoning. Based on this research, livestock producers are cautioned to avoid grazing pastures where water hemlock grows and to especially be aware of the potential toxicity and palatability of the immature seed heads.

Technical Abstract: Immature water hemlock seed heads caused the death of 9 cows in a herd of 81 in central Utah. This is the first documented case of poisoning and death in cattle from ingesting immature water hemlock seed. Field investigation of the poisoning and follow up diagnostic, chemical and toxicological evaluation determined that the immature water hemlock seed was the probable cause of the cattle deaths. Chemical analysis revealed cicutoxin, cicutol-like toxins and other polyacetylene compounds in the immature water hemlock seeds similar to the highly toxic compounds reported in the tubers/roots. Based on this finding and the follow up investigation, livestock producers are cautioned to avoid grazing pastures where water hemlock grows and to be aware of the palatability of immature water hemlock seeds and their potential toxicity.