Beware Of Retractable Leashes
Retractable/extending leashes can inadvertently teach your dog to pull on the leash when walking. Retractable leashes always create a slight tension on the leash, so when you use one your dog learns to ignore that tension. This bumps right up against teaching your dog to walk with you politely with a slack leash. To encourage polite – no pulling – on-leash behavior, stick with a traditional leash or  or use a a front-clip harness such as the Sense-ation (by Softouch Concepts) or the EasyWalk (by Premier). These front-clip harnesses work by using the force of the dog's own pull to turn him gently to the side, and most dogs seem perfectly comfortable wearing them right from the start. You can also discourage pulling by using a simple and intuitive technique: simply stop in your tracks whenever the leash is taut as opposed to slack.  Your dog will wonder what you are up to and will turn around and look at you. Once he does, you can continue moving with the slack leash. The moment there is tension on the leash between you two, stop again. Your dog will turn and look and you can begin walking again. It may take a couple "start/stop" walks for your dog to get the idea, but in a short time your dog will begin to realize that tension on the leash means the walk stop and not that you two will get the destination faster. Finally, if you want to give your buddy more room to explore while still being safely on-leash, consider using a long rope or an extra-long trainer leash. Training leashes come in a variety of lengths from about 20 feet to 50 feet. Knot the rope or training leash every 4 or 5 feet so you can pay out only portions of the line at a time. Using an extra long leash can be a little tricky, but done correctly it’s better and safer than an retractable leash.