I am not a fan of the retractable leash, also known as the "flexi-lead."

If you happen to be a proud owner of the flexi-lead, then just hear me out.  This particular instrument was made with good intentions, such as allowing your dog a little more movement so he's not so restricted when walking. However, it is a dangerous tool, especially because it's a problem even when it is being used the way it was designed.   

From a trainer's perspective, it's a terrible leash. It encourages a dog to pull and relinquishes any and all control you may have of your dog - unless of course he is well-trained already.

When you use this leash, you are rewarding your dog for walking away from you.  This leash allows the handler to slip into patterns where they aren't actually paying attention to the dog. It gives an owner a false sense of security that the dog is on a leash and therefore nothing can happen to him.

However, there's a lot that can and does happen to dogs on this type of leash. You will almost never see a trainer using this leash, unless they are doing certain "controlled" exercises. The only time I would advocate a leash like this is for potty breaks on a road trip and for doing controlled send out commands where you want the dog to move away from you and go to a selected space like a dog bed.   

Here's some examples of how it can be the wrong kind of leash to use.

*If a dog smells something, the dog starts to pull and the leash expands. If the dog sees something in motion, like a little critter, the dog is going to run fast and you may or may not be prepared for it. When you finally realize what he's doing you may try to stop the leash from expanding any further by grabbing it causing a very painful rope burn. Cringing in pain, you continue to try to stop your dog but now you've got a lot of leash out and the dog starts to wrap himself around either a person, or tree, or perhaps another dog. It's not going to be pretty. 

*If your dog approaches another dog without permission from the other dog's owner, and the other dog is not very friendly, you might find yourself dealing with a dog fight.  If this happens, you've got to worry about these two dogs getting tangled up in that flexi-lead.

*If you are walking on a sidewalk and your dog sees something on the other side of the road that piques his interest and taps his prey drive (like a cat, or squirrel) he may decide to dart across the road before you realize what's happening.  If there is a car coming while he does this, it's going to be pretty ugly.

*If you are walking him on a bike path like so many people do in this area along side the river, and a cyclist is coming the opposite way just about the same time your dog decides to investigate that tree, it could be very bad for everyone involved.

I certainly see the appeal to a leash like this, but once you become aware of the dangers you might reconsider using this for your walks.  If you do own one of these, please be aware of your surroundings at all times, and be respectful of other dog and dog owners who are just trying to get some exercise.  Just because you see another dog, it doesn't mean you have to stop and play with them.  Stay focused!