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Journal
Publications
Gates C.C., Elkin B.T., and Dragon D.C.
1995. Investigation, control and epizootiology of anthrax in a
geographically isolated, free-roaming bison population in northern Canada.
Canadian Journal of Veterinary Research. 59: 256-264. PDF = 814 KB)
Abstract
In July 1993 anthrax caused significant
mortality in an isolated, free-ranging population of bison (Bos bison
athabascae) west of Great Slave Lake in the Northwest Territories. There was
no previous record of anthrax in this area. An emergency response was
undertaken to reduce the scale of environmental contamination and
dissemination of anthrax spores and hence to reduce the likelihood of future
outbreaks. One-hundred-and-seventy-two bison, three moose (Alces alces), and
three black bear (Ursus americanus) carcasses were found. Visual detection
of carcasses was enhanced with the use of an airborne, remote infrared
sensing camera mounted externally on a helicopter. Fifty-five percent of the
carcasses were located in forested or shrub-covered sites where detection
would not have been likely without the thermal imaging equipment. Carcasses
were disposed of by incineration and the sites were decontaminated with
formaldehyde. Application of formaldehyde to carcasses prevented scavenging.
The outbreak occurred after a prolonged period of drying between April and
mid-July 1993 which followed several successive years of flooding of bison
habitat. The "spore concentration hypothesis" provides the most
conservative explanation for the occurrence of anthrax under the observed
conditions. |
