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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #359668
Title: Spontaneous outbreak of Astragalus pehuenches (Fabaceae) poisoning in cattle in Argentina

Author
item MARTINEZ, AGUSTIN - Instituto Nacional Tecnologia Agropecuaria
item LAUROUA, CATALINA - National University Of Central Buenos Aires Province
item BORRELLI, LAURA - Instituto Nacional Tecnologia Agropecuaria
item Gardner, Dale
item ROBLES, CARLOS - Instituto Nacional Tecnologia Agropecuaria

Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2018
Publication Date: 11/20/2018
Citation: Martinez, A., Lauroua, C., Borrelli, L.B., Gardner, D.R., Robles, C.S. 2018. Spontaneous outbreak of Astragalus pehuenches (Fabaceae) poisoning in cattle in Argentina. Toxicon. 157:84-86. https://doi.org/10.1016/j.toxicon.2018.11.303.
DOI: https://doi.org/10.1016/j.toxicon.2018.11.303

Interpretive Summary: This is a case report of an outbreak of poisoning by a locoweed plant (Astragalus pehuenches), commonly known as “Yerba Loca”, on a farm in the Patagonia region of Argentina. This is the first report and documented case of poisoning by this plant in cattle. Sixty three of 70 cattle died as a result of this case of poisoning. Tissue samples were collected postmortem from one animal and both the field clinical signs and the histological lesions of the poisoning are described. Samples of the locoweed were also collected and analyzed and found to contain the suspected toxin known as swainsonine which is found in North American locoweeds. This report will be useful for diagnosis of future cases of poisoning by this plant and will be used to inform livestock producers in this area of Argentina to the potential poisonous effects of this plant on grazing livestock.

Technical Abstract: This is the first report of a spontaneous outbreak of Astragalus pehuenches poisoning on a farm in Argentine Patagonia, where 63 out of 70 cattle died. The main clinical signs of affected animals were ataxia, balance loss and progressive emaciation. Purkinje cells presented vacuolation and marginalization of the nucleus. Astragalus pehuenches was detected in the paddock as well as in the ruminal content and fecal matter samples of the affected animals. Swainsonine concentrations in Astragalus specimens were found to be as high as 0.096%.