(PEM, CCN, polio, cerebrocortical necrosis)
Polioencephalomalacia is a disease of the central nervous system, caused by a vitamin B1 (thiamine) deficiency. Since the rumen manufactures B vitamins, polio is not caused by insufficient thiamine, but rather the inability to utilize it. The most common symptom of polio is blindness and star-gazing.
Polio most commonly occurs in lambs that are consuming high concentrate diets. Polio can also occur in sheep that consume plants that contain a thiamase inhibitor. Polio symptoms mimic other neurological disease conditions, but a differential diagnosis can be made based on the animals’ response to injections of vitamin B1.