I've only known one dog have a shock collar. It was a rescue mastiff cross and was lethal with cats, chicken, small dogs etc.(literally) the owners only used it for a week and the dog, after a lot more work is now a calm lovely dog that the cats sleep with. I think the dog would have had to be put down if the collar had not been used, but it was used sparingly, during training sessions and very carefully. I would never dream of using it on a small dog. In some parts of the UK they are illegal due to people using them for every little problem for an easy fix, appalling
