Causative agent: Parainfluenza 3 virus
In a 1991-92 serologic survey of bison in Yellowstone National Park, Wyoming, 36% of all bison tested had antibody titers to PI33 virus from 0 to 100% during the period 1977 to 1984. There was no observed clinical disease or decrease in productivity during this period. The source of the virus is thought to have been the cattle in the area (38).
virus (26). In Delta Junction, Alaska, free ranging bison demonstrated an increase in the prevalence of antibody titers to PI
Clinical signs:
There has been no known disease, or reduced productivity associated with PI3 infection in bison (38). In cattle, PI3 infection in concert with various stressors and other disease causing agents, has been associated with pneumonia (9).
As the population of bison in North America grows, the methods of production of bison will probably intensify. As this happens the various stresses placed upon bison will change. In other species raised under intensive management conditions, disease occurrence involves a complex interaction of infectious agents, management associated stressors, and environment associated stressors. Infectious agents, such as PI3 may begin to play a more important roll in the development of disease in intensively raised bison.
Diagnosis:
Exposure of bison to the virus may be diagnosed by submitting blood samples to a diagnostic pathology laboratory for serology.
Treatment:
Since there has been no disease associated with PI3 infection in bison, there is no treatment required.
Control:
At the present time vaccination programs to control PI3 infection in bison are not recommended.