No, as long as the collar fits the dog perfectly, and you know how to use the leash, it is not cruel. If the collar is too tight, it can be harmful to the dogs. Even moderate tight collars can result in skin irritation and hair loss. It is bad for them to wear such a tight period for such a long period. It is not cruel to put a collar on a dog; however, make sure that your dog is comfortable while wearing it.