The histopathologic diagnosis of subclinical Johne's disease in North American bison (Bison bison)

Vet Microbiol. 2000 Dec 20;77(3-4):325-31. doi: 10.1016/s0378-1135(00)00317-5.


The morphologic changes of subclinical Johne's disease in North American Bison (Bison bison) are characterized by microgranulomas composed of epithelioid macrophages and individual multinucleate giant cells of Langhans'-type occasionally containing individual cytoplasmic acid-fast bacilli compatible with Mycobacterium avium paratuberculosis. The microgranulomas are best visualized in the mesenteric lymph nodes of infected subclinical animals. Macrophages that can be confused with infection-associated epithelioid macrophages in the mesenteric lymph nodes are pigment-carrying cells from the intestinal tract. Mesenteric lymph node biopsy may be a useful diagnostic tool for detection of mild subclinical infection in individual ruminants from herds of unknown infection status. The biopsy may also be useful for Johne's disease surveillance during test-and-cull programs.

Publication types

  • Evaluation Study

MeSH terms

  • Animals
  • Biopsy / veterinary
  • Bison*
  • Female
  • Langerhans Cells / microbiology
  • Lymph Nodes / microbiology
  • Lymph Nodes / pathology*
  • Macrophages / microbiology
  • Mycobacterium avium subsp. paratuberculosis* / isolation & purification
  • Paratuberculosis / diagnosis
  • Paratuberculosis / epidemiology
  • Paratuberculosis / pathology*