It sounds like there is more going on with the story. You would have to be heartless to kill any pet and to the feed it to his dogs is cruel. Sounds like he was trying to cause hurt to the Sheep's humans.
It's a few years since I left the area, but family and friends assure me that it still goes on. Sheep stealing from the moors around Bradford and Halifax, that is. Was certainly upsetting the farmers around when I lived there 20 yrs ago. I'd better not say who were the strongest suspects.
What a sick thing to do.
If I'm not mistaken, if dogs kill a farmers sheep, the farmer has the right to shoot the dogs. What happens to stupid humans like this one?