Bovine anaplasmosis transmission studies conducted under controlled natural exposure in a Dermacentor andersoni = (venustus) indigenous area of eastern Oregon

Am J Vet Res. 1977 Mar;38(3):351-4.


In Anaplasma marginale transmission studies conducted on the high semi-arid range of eastern Oregon during the 1974 and 1975 vector season, A marginale-susceptible calves (principals) were maintained on 2 raised tick-proof platforms. Anaplasmosis-susceptible control calves of approximately the same age and latent-infected cows grazed the area surrounding the platforms. One latent-infected steer spent the entire 1975 vector season on a platform with the principals. The 28 principals did not develop anaplasmosis, whereas 15 of 30 (50%) controls became infected. The disease was not transmitted from the latent-infected cattle to the principals exposed only to flying hematophagous insects, whereas 50% of the controls exposed to the Rocky Mountain wood tick Dermacentor andersoni) = (venustus) developed the disease. Dermacentor andersoni appears to be the principal vector on this range.

MeSH terms

  • Anaplasmosis / immunology
  • Anaplasmosis / transmission*
  • Animals
  • Arthropod Vectors*
  • Cattle
  • Cattle Diseases / immunology
  • Cattle Diseases / transmission*
  • Ceratopogonidae
  • Dermacentor*
  • Diptera
  • Female
  • Male
  • Oregon
  • Ticks*