Paratuberculosis (Johne's Disease)

Johne’s (pronounced “Yoh-nees”) disease is a chronic, contagious enteritis characterized in cattle by persistent diarrhea, progressive weight loss, debilitation, and eventually death. It is caused by the bacteria Mycobacterium paratuberculosis, also known as Mycobacterium avium subsp paratuberculosis, is believed capable of infecting and causing disease in all other ruminants including sheep, goats, camelids, and in captive and free-ranging cervids.

M paratuberculosis is excreted in large numbers in the feces of infected animals and in lower numbers in colostrum and milk. It is fairly resistant to environmental factors and can survive on pasture for more than one year and even longer in water. Infection is acquired early in life, but clinical signs rarely develop in cattle less than two years old.

Dr. Ken Newens serves as Colorado’s Johne’s Disease Coordinator. As positive laboratory cases are diagnosed, Dr. Newens will contact the testing veterinarian to provide consultation and assistance to the veterinarian and producers in conducting risk assessments and development of testing and herd management strategies.

Laboratory Testing

The Colorado Department of Agriculture Animal Health Lab (CDAAHL) is the state laboratory with the Colorado Department of Agriculture. CDAAHL offers ELISA and direct fecal PCR for Johne’s testing. Visit the CDAAHL website to learn more.


The Merck Veterinary Manual: Overview of Paratuberculosis

Colorado Voluntary Bovine Johne’s Disease Control Program

Johne’s Disease Q&A for Bovine Producers

Johne’s Beef Brochure