Clinico-pathological findings in cattle exposed to chronic bracken fern toxicity

Abstract AIM: To describe changes in blood and urine analytes in a large group of cattle exposed to chronic bracken fern toxicity, in order to identify parameters of potential diagnostic value. METHODS: The study was conducted on two livestock farms on which bovine enzootic haematuria (BEH) was known to occur; Farm A grazed a local breed of cows and Farm B grazed Friesians. Group A1 comprised 66 cows from Farm A, Group B 54 cows from Farm B, and Group A2 13 heifers from Farm A. Ten healthy cows were used as controls. A complete physical examination was performed (Group A1), and blood (all groups) and urine (Groups A1 and B) samples were collected. Necropsies and histopathology were undertaken on four cows. RESULTS: Anaemia, leucopenia, monocytosis, thrombocytopenia, hypergammaglobulinaemia, microhaematuria and proteinuria were detected. Multivariate statistical analyses established three phases of the disease of increasing severity; an initial phase, characterised by an extremely high monocytosis and othe...