An Outbreak of Sheep-Associated Malignant Catarrhal Fever in Bison (Bison Bison) after Exposure to Sheep at a Public Auction Sale

Abstract

Abstract. An outbreak of malignant catarrhal fever (MCF) among bison sold at an auction market was studied for an 18-month period. Forty-five of 163 bison submitted for sale from 8 different bison farms died on 7 other destination farms. The outbreak began on day 50 after the sale, peaked between days 60 and 70, and ended on day 220. Twenty-one dead bison were confirmed to be MCF cases by clinical histories, pathology, and detection of ovine herpesvirus-2 DNA in their tissues with polymerase chain reaction assays. Twenty-four dead bison were classified as suspect MCF cases from clinical histories. No cases of MCF were observed among bison remaining on originating farms or resident bison mixed with sale bison on destination farms. There were no sheep reported within 3 km of originating or destination farms, limiting bison exposure to sheep to the auction facility, where sheep were present for less than 1 day. The outbreak provides an illustration of the temporal distribution of MCF mortality expected in bison and an estimate of the time from exposure until death from MCF after a single short exposure to sheep. The study provides evidence that bison with MCF do not transmit MCF to other bison.

The Pathology of Malignant Catarrhal Fever, With an Emphasis on Ovine Herpesvirus 2

“…73,133 No shedding of infectious virus occurs from clinically affected susceptible hosts. 7 Ovine Herpesvirus-2 and Domestic Sheep (Ovis aries)…”

“…While of minor importance for domestic cattle, MCF is economically important in the North American bison industry, 7 for captive and free-ranging cervid species,* to managers of zoological collections 40,43 and to producers of domesticated species such as Bali cattle (Bos javanicus) and domestic water buffalo (Bubalus bubalis). 28,45,46,84,114,141 Veterinary pathologists working with zoological collections play a useful role by reporting the impact of members of the MCFV group on captive species.…”

“…In the wake of that owner's outbreak, it quickly became clear that MCF was of appreciable importance to the commercial bison industry in the United States and Canada. 7,94 The long history and intriguing nature of MCF (Table 1) were small solace to the Colorado producer in the absence of practical solutions from MCF researchers. A total of 27 bison died as a result of the outbreak.…”

Sheep associated malignant catarrhal fever: an emerging disease of bovids in India

“…Some species appear to be particularly susceptible, for example, Pére Davids deer [67], Bali cattle [88] and bison [10]. Deer mostly die within 48 h of the appearance of the first symptoms and bison within three days [61].…”

“…A typical feature of MCF in cattle is that many outbreaks are sporadic, with single or only a few individuals in a herd being affected. It is because of this feature, MCF is usually not recognized as a major cause of economic losses to cattle husbandry; however, outbreaks of MCF have been recorded in domestic cattle, deer and bison herds causing huge economic losses [10,14,22,31,48,49,61]. In regions where mixed farming of the carrier species and the susceptible species is practised, MCF is a notable disease e.g.…”