Description: The lamb in this picture is exhibiting ataxia caused by an inflammation of the brain due to thiamin deficiency. This neurological syndrome is called polioencephalomalacia (PEM) and if untreated is potentially fatal. The lamb was treated with injectable thiamine and made a full recovery. PEM can also occur in functional ruminants where ruminal thiamin is destroyed by thiaminase. The thiaminase can arise from abnormal rumen bacteria (bacillus thiaminolyticus), or can come from plants such as bracken fern. Ruminal thiamin can also be destroyed by excessive sulfite. In Europe, this disease is called Cerebro-Cortico Necrosis (CCN).