Diseases of dairy animals: infectious diseases: Johne's disease

Authors: Stabel, Judith; COLLINS, M - University Of Wisconsin

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/1/2020
Publication Date: 12/1/2020
Citation: Stabel, J.R., Collins, M.T. 2020. Diseases of dairy animals: infectious diseases: Johne's disease. Book Chapter. (3)786-792. https://doi.org/10.1016/B0-12-227235-8/00219-4.
DOI: https://doi.org/10.1016/B0-12-227235-8/00219-4

Interpretive Summary:

Technical Abstract: Johne's disease is a chronic, debilitating intestinal disorder in cattle, sheep and wild ruminants, characterized by diarrhea, weight loss and death. Animals usually become infected as neonates via ingestion of faeces or milk containing the causative bacteria. However, clinical signs of disease may not present themselves until the animals reach 3 to 5 years of age or even older. During this time the animal is infected and may be shedding the organism in its faeces without demonstrating any clinical signs of disease. Although reduced production is a hallmark of infection, more importantly, these animals present a potential infective threat to the rest of the herd. Johne’s disease is difficult to diagnose and therefore to control. Diagnosis of infection is most frequently performed by direct culture or PCR of Mycobacterium avium subsp. paratuberculosis from the faeces or by indirect measurement of antibodies in the serum and milk. Control measures for paratuberculosis include management at the herd level to reduce exposure of susceptible neonates to contaminated manure or milk. Vaccination is another management tool that is becoming more widely used. Although Mycobacterium avium subsp. paratuberculosis is not classified as a zoonotic agent, it has been detected in tissues from some patients with Crohn’s disease, an inflammatory bowel disorder in humans. To date the association of Mycobacterium avium subsp. paratuberculosis with human disease is unclear.