By Dr. Paula Menzies and Dr. Jocelyn Jansen
Johne’s disease (pronounced yonee’s) is a disease of ruminants characterized by wasting and terminally, by diarrhea. It is caused by a bacteria called Mycobacterium avium subspecies paratuberculosis. Johne’s disease has been reported in Canada in cattle for several decades. Although it has also been reported in sheep for many years, no one is certain of how widespread it is or exactly how much damage it is doing to our sheep industry.