An outbreak of polio-encephalomalacia in cobalt-deficient sheep

Abstract

Extract

In New Zealand two forms of polio-encephalomalacia have been recognized in sheep. The mild form is characterized clinically by blindness (amaurosis), and pathologically by laminar necrosis of the cerebral cortex (Mullins et al., 1958). The severe form is characterized clinically by a wide variety of neurological signs and pathologically by extensive cerebro-cortical necrosis (Hartley and Kater, 1959). The mild form has a relatively high morbidity and low mortality, whereas the severe form has a low morbidity and a very high mortality.