Description of an outbreak of "fescue foot" in beef cattle in Buenos Aires province, Argentina

An outbreak of chronic lameness in adult cattle in a breeding herd in Buenos Aires province, associated with dry gangrene of the extremities due to consumption of Schedonorus arundinacea infected with the endophyte fungus Epichloë coenophiala, is described. The outbreak occurred during July 2022, in a herd of 50 lactating Aberdeen Angus cows, of which seven (14 %) presented clinical signs. Fescue consumption was by direct grazing, with a daily permanence of 8 hours for approximately 60 days. Diagnosis was based on epidemiological and clinical evidence and microscopic analysis of the pasture, which showed 70 % endophytic infestation by Epichloë coenophiala.