Anthrax crops up in livestock in small numbers from time to time. The Ministry usually deal with it pretty quickly so I wouldn't lose sleep over it
Probably a few spores imported on all those Afghan trophies.
Before he retired my Dad was a vet in Smoerset and they had several farms with a history of anthrax. I used to go on his rounds with him and every so often I would be told to stay in the car while he took a blood sample from an unexplained death, just in case. He had a few scary days following an incedent when a farmer cut the throat of a sick cow and sent it off to the abbatoir where they noticed the spleen was enlarged so they put it in a plastic bag and took it into the surgery! It was a confirmed case but was contained. I think he said it responds to pennecillin if used quick enough.