Yes I suspect that laid poison could be around, not so much for foxes as against the Japanese knotweed. The pigs love that and eat it on her side, but the owner of the woods may have tried to get rid of his by herbicide. Too late for a post mortem but I will let her know for if it happens again. Better fencing is in order too. I've no idea what herbicides would be used against Japanese knotweed, as we never use anything like that, but does anyone know what could be so quickly lethal?
The tup is a Hebridean, Hilarysmum. We keep the old fashioned multihorned variety and Laughing Boy in the picture is an old softie !