As I was there helping with the shooting and gutting of those, i cant recall I noticed any signs of mixy on any, they were all perfectly healthy looking. The land we took these from is very productive land and a loss of a number like this really is only a couple of percent of the true population, we'd probably be able to repeat this several times a month and still leave plenty to go at the next season.
As Ian said, he has a LOT of permission with a lot of pests that the landowners want gone, be it rats, rabbits, foxes and corvids etc.
I have a couple of tiny plots in comparison and