Case introduction
An outbreak of abortions in a multi-site “high health” breeding pig farm system was investigated. The system was located in isolated farm sites in southern Australia. These isolated locations are features of many Australian pig farms, which provide excellent biosecurity. Australia has also remained free of PRRS and several other major infections endemic to Europe and America, so farms are generally clean with a high health status. However, this long period of pig industry isolation and restricted imports of live pigs has also led to a limited pool of modern pig breed genetics.
An increased number of abortion cases were noted at a nucleus multiplier farm known as St Arnaud 2-3, with 5 % of weekly farrowings affected. The affected pigs appeared exclusively in the first parity gilt section of the farm. Examination of affected are represented in this picture – numerous aborted foetuses are clearly mummies and have been dead in utero for some time. The number of piglets expelled is probably a litter of normal size.