Johne’s Disease (JD) Johne’s disease (JD) is a chronic and contagious disease of cattle and other domestic ruminant species (such as sheep, deer, goats and alpaca) caused by infection with the bacterium Mycobacterium avium subspecies paratuberculosis, or ‘MAP’ for short. The disease (sometimes also called paratuberculosis) is named after the … Continue reading Dairy Cows