Anthrax in swine

Anthrax is caused by Bacillus anthracis. It is highly virulent, and once access to the animal's body is gained, it multiplies quickly, invades the blood stream and produces a rapidly fatal blood infection. In the presence of oxygen the bacilli form spores which are remarkably tenacious, highly resistant to heat, low temperatures and chemical disinfectants, retaining viability for many years in both soil and water and upon hides or contaminated objects held in storage.

Animals of all species are susceptible to anthrax to some degree. Cattle, horses, sheep and goats are those most frequently affected. Swine apparently possess some natural resistance but anthrax does occasionally appear in them.

Risk to Swine From Anthrax Considered Low

The Western College of Veterinary Medicine says, despite the deaths of three pigs in Saskatchewan from anthrax, the risk of swine becoming infected remains extremely low. Figures released by the Canadian Food Inspection Agency show 663 animals on 143 Saskatchewan farms, including three pigs on one small outdoor swine operation, have died this summer from anthrax. Anthrax is caused by a soil borne bacterial spore which must be eaten to cause infection.   Western College of Veterinary Medicine associate professor Dr. John Harding says anthrax is very rarely reported in swine: “We normally see ruminants, particularly cattle, sheep, bison being most susceptible to anthrax. Swine are very rarely infected, resistant. The swine today that would be infected would invariably be either outside animals in contact with spores residing in the soil or have contact with dead animals, i.e. if there's a mixed swine and cattle farm and swine were able to consume dead animals that had died of anthrax, i.e. mixing with cattle and dead cows.That would be a second possibility.The third possibility would be through contaminated feed that had been made with meat and bone meal that happened to get into the rendering system but, with the recent ban on SRM's, I think that would be very unlikely to happen but there are outbreaks in history that are referenced in the text books that probably meat and bone meal was the primary source of contamination.” Dr. Harding says anthrax will be extremely rare in modern systems where pigs are housed indoors under good biosecurity. He suggests the only swine on the prairies likely to be at risk for anthrax would be feral swine living outdoors all the time or domestic swine outside on pasture.

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