Don`t have much knowledge about lurchers mate, and not sure if someone else has posted this. But a lad who drinks down our local pub is big into em, he had a very similar problem with a young dog, and seen as it was our sheep he went after it needed sorting!! So he brought it down the farm, we got one our big texel tups, put him in a small pen made of fencing hurdles, chucked the dog in, stood back and let nature take its course. Pretty much Instantly solved his problem, dog never looked at a sheep again!
ATB The 12...3