Wimmera rye grass toxicity in Western Australia

Outbreaks of Wimmera rye grass toxicity in the south-west of Western Australia, and the associated distribution of Wimmera rye grass parasitised by Anguina sp and Corynebacterium sp were investigated. Between 1970 and 1974, 58 outbreaks occurred on 26 farms in sheep and cattle grazing pasture, cereal crop, stubble, screenings, or hay containing parasitised Wimmera rye grass. Morbidity rates up to 77% were observed. Clinical signs were characterised by staggering, collapse, periods of convulsions and other nervous signs, often followed by death. A pale, friable liver and haemorrhages in different organs were the most constant gross autopsy findings, but no specific histopathological changes were observed. Symptomatic treatment of affected animals and agronomic control measures attempted by farmers were unsuccessful in controlling the disease.