Bovine enzootic hematuria in the Southern Cone of Rondônia

Abstract

Radiomimetic plants are those that can mimic the effects of radiation. Ferns of the genus Pteridium are the main plants with this characteristic. The ingestion of bracken fern results in three forms of clinical disease in cattle: one acute, called hemorrhagic diathesis, and two chronic ones, in the form of squamous cell carcinomas in the digestive system and bovine enzootic hematuria (BEH). Although Pteridium spp. occur in the state, there are no reports of poisoning in Rondônia. The objective of this study is to describe the epidemiological, clinical, and pathological features of BEH caused by Pteridium spp. consumption in Rondônia. The investigation began with the histories of rural properties in the Southern Cone of Rondônia that had cattle with diseases compatible with BEH. These properties were visited, the pastures and herd were inspected, and the disease history was compiled. Epidemiological and pasture data from seven rural properties were analyzed. Pteridium esculentum invaded grazing areas on seven properties, and all owners reported hematuria in cattle on these properties. On one property, a nine-year-old female Nelore cow presenting clinical signs of BEH was euthanized and necropsied. The gross damage was confined to the urinary bladder and characterized by marked, diffuse thickening of the bladder wall and mucosal nodules. Histopathology and immunohistochemistry revealed nonpapillary and infiltrating transitional cell carcinoma. On three rural properties with a history of BEH, Pteridium was absent in the pastures, but ferns characterized as Christella conspersa and Pityrogramma calomelanos were present. The epidemiological, clinical, and pathological findings confirm the occurrence of BEH associated with the consumption of Pteridium spp. in the Southern Cone of Rondônia. Further research is needed to determine the role of other ferns in the development of BEH.