FORT ST. JOHN, B.C. - Thirteen bison on a farm in northeastern British Columbia died of naturally acquired anthrax, a bacteria that the Agriculture Ministry says can remain dormant in certain soil conditions for many years.
The animals are thought to have contracted the disease from exposure to dormant anthrax spores in the soil of a feeding site on a farm near Fort St. John, the ministry said in a statement.
“This is the first documented case of anthrax in livestock in B.C.,” said Jane Pritchard, the province's chief veterinary officer.
“It was quite shocking when we actually got the first test that suggested that it was anthrax. We repeated that twice more because it's that unusual. We basically did every test we possibly could do to try and rule it out until we had access to the molecular test.”
The animals began dying last week, samples were sent to the lab on Friday and the diagnosis was made Monday, she said.
The disease has been reported in the Peace River region of Alberta, and that same soil goes right across the border into B.C., Pritchard added.
“The spore of the bacteria of this disease has a preference for certain soil conditions and those are the conditions that were present in British Columbia in this area.”
A disturbance in the soil or unusual weather conditions could have brought the spores up to the surface, causing the animals to be exposed to them, she said.
She said the bison corpses were placed on a brush pile and burned.
The ministry statement said the site is no longer being used and the farm has reported no other losses in its remaining herd of 150 animals.
A vaccine for anthrax for livestock is available and the ministry said exposed animals can be successfully treated if diagnosed early.
It said anthrax can affect humans, although it's very rare and there is no indication that anyone in contact with these animals has been infected.