The initiative for the Johne's Disease Control Program has three objectives:

  • Reduce the possibility of introducing Johne's disease into uninfected herds.
  • Minimize the impact of Johne's disease in herds already infected.
  • Control existing cases.

Johne's (pronounced "Yo-knees") is a contagious, chronic and usually fatal bacterial infection (Mycobacterium avium subspecies paratuberculosis), a hardy bacteria related to the agents of leprosy and tuberculosis, primarily of the lower small intestine. Johne's most often infects dairy and beef cattle, sheep, goats, and other ruminants by invading the walls of the intestinal tract.

Typical clinical signs include diarrhea (maybe intermittent, maybe ongoing), with a normal appetite, weight loss, decreased milk production, increased incidence of mastitis, prolonged calving interval, emaciation and then death. Several weeks after the onset of diarrhea, a soft swelling may occur under the jaw (bottle jaw). That swelling, also known as intermandibular edema, is due to protein loss from the bloodstream into the digestive tract. Animals at this stage of the disease will not live very long, perhaps a few weeks at the most. During that time however, the infected animal may be shedding large amounts of the bacteria in its manure, serving as a source of infection for other animals. Johne's disease should be considered a herd problem as well as an individual problem.


  • Johne's Disease Q & A for Goat Owners
    This publication is provided by Wisconsin Department of Agriculture, National Institute of Animal Agriculture, National Johnes Education Institute, USDA APHIS Veterinary Services and School of Veternary Medicine - University of Wisconsin - Madison