Johne’s vaccine in the United Sates is only approved for use in cattle. Due to human health risks, interference with Johne’s ELISA testing, and interference with tuberculosis testing, use of the vaccine is restricted. It must be administered by a Johne’s vaccine certified veterinarian. If vaccinated animals are tested for Johne’s disease, fecal culture or PCR must be used. Vaccinating herds will have more animals test positive to screening tests for tuberculosis which may result in more herd quarantines until confirmatory testing is done. Confirmatory TB testing will usually clear vaccinated animals.
Participation in a Johne’s disease vaccination program in Wisconsin requires a herd to meet certain requirements. Your veterinarian can explain these requirements. If you decide to vaccinate your herd after consulting with your veterinarian, you must also meet with a veterinarian from the Division of Animal Health (DAH) and sign an agreement. Ask yourself these questions first:
- Have I tested my herd using fecal culture or PCR and found at least one animal or environmental sample positive?
- Does my herd have a moderate to heavy rate of Johne’s disease?
- Will my calves be exposed to manure from adult cows?
- Have I seen clinical cases of Johne’s disease in home-raised animals?
- Have I seen clinical cases of Johne’s disease in 1st and 2nd lactation (or younger) home-raised animals?
- Do clinical cases of Johne’s disease account for 10% or more of my culls?
If you answered "yes" to more than one of these questions, vaccine may be a useful tool on your farm. Although many herds in Wisconsin have benefitted greatly from vaccine use, it is important to remember that vaccinated animals can still become infected and serve as a source of infection to other animals.
Contact your herd veterinarian for more information.