Pteridium aquilinum (bracken fern) toxicity in cattle in the humid Chaco of Tarija, Bolivia

We studied the toxicity caused by chronic ingestion of Pteridium aquilinum (bracken) in cattle in the humid Chaco of Tarija, Bolivia. Bovine enzootic haematuria (BEH) and Carcinoma of the esophagus (CE) affected the herds. Si ck animals showed caquexia, anemia, leucopenia and urine that turned from p ink to intense red color with the presence of blood clots. Cattle grazed in the humid Forests of the mountains where P aquilinum represented more than 50% of the plants. P aquilinum var arachnoideum and P aquilioum var Caudat um were present. Toxic norsesquiterpene. ptaqulloside, was identified in bo th varieties. Carcinomas were in the urinary bladders and esophagus of 100% and 50% of the cattle, respectively Control of the intoxication could be d ifficult due to geographic characteristics of this Bolivian region.