Case report

Polioencephalomalacia (PEM) is a neurologic condition in ruminants that can be caused by several dietary factors including water deprivation-sodium ion toxicosis, lead poisoning and high sulfur intake. Three month old calves on a 1500-cow dairy experienced neurologic problems during three separate episodes. The morbidity rate approached 75% each time. Based upon post-mortem examination, three of the affected calves were diagnosed with PEM. The history revealed a change in the formulation of the pelleted feed four days prior to the initial outbreak. Wet chemistry analysis of the pelleted feed revealed a sulfur content of0.56% (dry matter basis), which was considered to be the cause of the PEM outbreak.