Animal HealthDiseasesJohne's Disease

Johne's Disease


What Is Johne’s Disease?
What kind of animals can get Johne’s Disease?
Signs of Johne’s Disease
Testing for Johne’s
Preventing Johne’s
Can Johne’s be treated?
Additional Information

What is Johne’s Disease
Johne's disease (pronounced "yo-knees") is a contagious, chronic and usually fatal infection that affects the small intestine of ruminants. All ruminants are susceptible to the disease. Also known as paratuberculosis, Johne’s is caused by a hardy mycobacterium related to the causative agents of leprosy and tuberculosis. The disease is worldwide in distribution.
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What kind of animals can get Johne’s Disease?
Johne's primarily affects ruminant species (hoofed mammals that chew their cud and have a chambered stomach) such as cattle, sheep, goats, deer, antelope and bison. It is particularly common in dairy cattle because they are, due to management practices, more frequently exposed to the organism that causes the disease. Infected ruminants have been reported from all parts of the world.  Non-ruminants such as omnivores or carnivores (birds, raccoons, fox, mice, etc.) may become infected, but rarely become sick.
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Signs of Johne's
Signs of Johne’s include weight loss and diarrhea with a normal appetite. Several weeks after the onset of diarrhea, a soft swelling may occur under the jaw (bottle jaw) due to protein loss from the bloodstream into the digestive tract. Animals at this stage of the disease typically do not live long. Signs are rarely evident until two or more years after the initial infection, which usually occurs shortly after birth.  Animals are most susceptible to infection in the first year of life. Newborns most often become infected by swallowing infected manure from the birthing environment or udder of the mother.  In addition, newborns may become infected while in the uterus or by swallowing bacteria passed in milk and colostrum.  Animals exposed at an older age, or exposed to a very small dose of bacteria at a young age, are not likely to develop clinical signs of the disease until they are older than two years.
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Testing for Johne’s
New approaches are available for testing that are cheaper and more reliable than ever before. The three common ways to test a herd for Johne's are: A culture of fecal samples (individual or pooled; collected directly from the animal or the barn or pasture), direct PCR with the same types of samples, or tests on blood or milk samples for antibodies by the animal in response to MAP infection. Consult with your veterinarian to select the best approach for you and your animals. 
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Preventing Introduction of Johne's Disease
Johne's disease usually enters a herd when healthy but infected animals are introduced to the herd. Herds that are not infected should take precautions against introduction of the disease. Such precautions include keeping a closed herd, or requiring that replacement animals come from test-negative herds. Some best management practices include:

  • Keep birthing areas for calves, lambs, kids, etc., as clean as possible.
  • Reduce newborn exposure to manure from adult animals, by separation if possible.
  • Avoid manure contamination of feed by using feed bunks and not using the same equipment to handle feed and manure.
  • Avoid manure contamination of water sources where animals drink.
  • For natural colostrum needs of newborn animals, use colostrum from Johne's negative animals.
  • Do not pool colostrum.
  • Avoid natural nursing and milk feeding whenever possible. Feed an artificial milk replacer or pasteurized milk instead of raw milk to supply the needs of newborns.  Never feed pooled milk or waste milk.
  • Thoroughly clean the udder and teats before collection of the colostrum to avoid manure contamination.
  • The causative bacterium can survive up to a year in the environment. If pastures are contaminated, till the grounmd or graze using non-replacement feeder cattle.
  • Identify all females in the herd.  Identify and remove, or keep separate all test positive animals.
  • Prevent infection from spreading by culling, or separating offspring of infected mothers, as soon as possible.
  • If purchasing herd additions, try to buy from low-risk herds.  Some producers enroll herds in the Voluntary Bovine Johne’s Disease Control Program to identify their herd as low risk.
  • Work with your veterinarian to develop a strategic plan for Johne's prevention and control for your farm.  Consult with them about which Johne's test is best for your situation and use a test certified diagnostic laboratory.

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Can Johne’s be treated?
No.  In the few studies that attempted to treat Johne's disease with antibiotics, symptoms appeared to subside but animals relapsed after therapy was halted. As with other mycobacterial infections (for instance, human tuberculosis) multiple antibiotics must be injected or given orally daily for months. For most animals, this is cost-prohibitive as well as infeasible.
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Additional Information
USDA-Animal & Plant Health Inspection Service/Veterinary Services overview
University of Wisconsin Johne’s Information Center
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