Short leashes are most helpful for dogs who're still learning the training ropes, but they can even be helpful for mature, well-trained pooches at times. While you probably don't want to use one of these leashes constantly, they can be helpful in a select few situations:

You're trying to help your hound build good walking habits.
You need some extra control for a reactive dog.
You need to teach your doggo good people manners.
Your walks often occur near cars and traffic.
You need to negotiate tight spaces with your dog.
Your dog performs service or therapy work.