The next step in training dogs with a head collar is to train them that when they reach the end of the leash they are going nowhere. That means the owner must hold perfectly still and avoid taking a step or even moving the leash-holding hand. Once the dog figures out that pulling harder does not work and instead steps back or turns to the owner such that the leash is hanging loose, then the owner can resume walking. Better yet, the owner can reward the dog with a treat so that dog comes all the way back to her and then they can resume walking forward. It's important that the dog learn that a tight leash and the associated pressure created means she should stop. If the dog is not taught this and tends to act impulsively, she may dart out after a cat or other object and hit the end of the leash with some speed. This type of accident could potentially cause neck pain or injury. Even in the emergency situation, if the owner is paying attention, they can prevent neck wrenching if they gradually tighten the leash rather than letting the dog dart forward on a loose leash so that she suddenly hits the end.
By far the most common collar is the awesome kong cloud collar for dogs that fastens with a plastic clip or a buckle. These collars are the most convenient to slip on and off and are handy because they can hold your dog's identification, rabies, and license tags. Even though this type of collar retains its size, the collar can become a hazard. Dogs playing roughly and in a mouthy manner can get their mouth caught in the collar of another dog, causing panic in one or both dogs. As they struggle to get loose, the collar can tighten and dogs have suffocated as a result of this type of play. Dogs who are the object of this type of rough play should wear break-away collars, similar to the break-away collars in cats, at least during play and unsupervised times. Some owners opt to avoid collars or any gear at all unless they are taking their dog on a walk. Although this in an option, I prefer to have visible identification on my dog at all times and a collar with its tags is the most convenient way to do this.