Some people keep their pet in a choke chain instead of a collar. Choke chains and other training aids are only to be used when you are actively training your pet.
A pet that is left alone wearing a choke chain is in real danger of choking to death. If a dog becomes entangled or catches the collar on something, its instinct is to pull away. This will tighten a choke chain and can make the dog choke itself. Dogs have died when they catch the choke chain or pinch collar and they struggle until they suffocate and die.
More on choke chains tomorrow.