This is an emerging disease in the deer industry in that the more you start looking for it the more you find it. It is estimated that the disease could be costing New Zealand deer farmers up to $5 million dollars per year in lost production. Clinically affected deer lose weight and develop a chronic scour, which is unresponsive to treatment; it can look like the after effects of a bad dose of facial eczema. Two clinical syndromes are seen, the odd sporadic case in older deer, or serious outbreaks in 8 to 15 month old deer with up to 15% of the mob affected. Control options on seriously affected farms are currently limited to culling affected stock, culling test positive animals, or depopulation of farms and restocking after two years. Current methods of laboratory diagnosis especially of subclinical animals are however unreliable and not suitable to use in any control programme.