Polioencephalomalacia of sheep and cattle.

Polioencephalomalacia was confirmed histologically in Western Australia in sheep from 100 farms and cattle from 14 farms during the period 1965 to 1974. The condition affected sheep and cattle in good physical condition of all ages, throughout the year. Mortality rates in sheep flocks ranged from less than 1% to in excess of 10% and occurred under a number of management systems.