Internet e-mail lists are full of dire warnings about them. Many trainers despise them. Some parks actually prohibit them. What exactly is the problem with retractable leashes such as the Flexi leash?

I’m a dog trainer, work as a kennel and dog show assistant with a Malamute breeder and train my own two dogs for obedience and sports, so it’s safe to say I’ve spent a lot of time around both good and ...