We are once again seeing several cases of P.E. (polio encephalomalacia), a nervous disease seen primarily in calves and younger stock.  P.E. is caused by a lack of vitamin B1 (not to be confused with a cobalt deficiency, which is associated with a vitamin B12 deficiency).  P.E. is thought to be nutritionally induced, when there is a sudden change in diet from stalky, higher DM diet, to a lush, low fibre diet.  A high dietary sulphur intake, especially with brassica's, has also been incriminated as a cause of P.E.  Calves with P.E. appear blind, may walk aimlessly, appear wobbly, have muscle tremors and head press.  If calves are treated early in the disease process with a series of vitamin B1 injections, survival rates are good.  In an outbreak situation we have had good success, by prophylactically treating the remaining, unaffected calves, in the group with an oral vitamin B1 drench.  This has proved a very cost effective preventative measure.