My take on retractable leashes:
Before I had a dog, I thought the concept was pretty convenient.
After I got a dog, I learned to immediately hate the retractable leash.
I actually own a retractable leash for a medium sized dog that reaches 26ft or 28ft away. I used it with Sammy when I first got her so that she could run on the beach. I also used it when taking her in the yard to potty. These scenarios were okay. Whenever we are walking on a sidewalk or around people, I lock the retractable leash with her next to me. Even with a retractable, I was still getting my dog under control when it was necessary to.
The problem with retractable leashes is that;
1.) They are not always reliable leashes. A dog can easily hit the end of the leash and break it.
2.) If the leash does not snap when the dog hits the end, your dog could potentially do a 360 in the air. It's happened! Imagine how bad that is for your dog's neck. Think of the health risks involved, and the potential damage it could do to your pet!
3.) People are ignorant and do not know how to use them properly. That's what it boils down to, in my opinion.
I work at a pet supply store and I see a lot of people using retractable leads. I always try to encourage normal 4ft-6ft leashes, but some people insist on using retractables... Some scenarios that I have witnessed on more than one occasion;
1.) People will let their dogs run up to anyone or anything. This can be extremely dangerous for the sake of the dog. With their owners not paying attention, I have seen dogs run up to other dogs who were NOT quite as friendly. In such cases, the dog on the retractable leash could get injured by another pet! This is also extremely unpleasant for people if the dog runs up to them, and jumps on them! No one really wants a dog to jump on them, especially a larger dog.
2. People will let their dogs roam around while they shop down the aisles. While the owner is busy looking at products, she doesn't notice Fido pissing on every corner of every aisle in the department... Not only that, but sometimes we don't find these accidents and they dry on the floor. We try to keep the store clean, but if owners don't take responsibility for their pets, or don't inform an associate so that WE can clean up the accident, the urine will dry up and this could pose a health risk for other dogs (especially young puppies... because too many people bring puppies in who are several weeks old, but have only had one or two sets of shots... This does not exactly mean they are covered for life just yet! It's safer to NOT put your puppies on the ground, ESPECIALLY at a pet store). Don't blame the store. Blame the ignorant/irresponsible pet owners who don't even have the decency to LET US KNOW. Accidents happen. We don't mind cleaning up after other dogs. The annoying thing is that no one comes to inform us. This could also be a risk factor for PEOPLE, too. Someone could slip and fall... It's sooo frustrating that people let their dogs wonder around.
3.) Just the other night a customer who comes in several times a week with her Yorkie was shopping on the dog toy aisle. I was on the opposite aisle, oblivious to her at the moment, as I was speed-walking back to the front with the information I had gathered for another customer. As I turned the corner, I almost stepped on her Yorkie who had come around the corner, too, and walked right into my path. He is a small dog, and she was at least 8ft away from him, down the toy aisle... I am 200lbs. Can you imagine if I had stepped on that dog, who is probably between 5-10lbs? Oh my god...
4.) Then if your dog has certain aggressive tendencies, or doesn't always get a long with every dog or person it meets, you DEFINITELY don't want to use a retractable. We had a man with an aggressive German Shepherd on a retractable and was letting it walk around at it's own desire, but was telling other customers to keep their dogs away because he was mean... Seriously?
5.) Retractable leashes can be extremely hazardous. Some people just let their dogs walk around customers and entangle them in the cord. This can make someone trip, OR they could get a burn from the cord. Even with jeans on, that cord can SERIOUSLY hurt someone. If a dog bolts past someone and burns their legs, or cuts the back of their knees, OUCH!!!
6.) Several months ago a man came in with two VERY large Rottweilers. They were on retractable leashes, PULLING TO THE EXTREME, and wandering around as they pleased. One actually approached me, with the owner even knowing, and jumped up on me to say hello. That's nice and all, but this dog was MASSIVE and the weight alone could have dropped me to the ground. Imagine if I had been an old lady instead? Imagine an elder vs. a bull dozer. Yeah... kind of like that...
People need to LOCK their retractables and USE THEM WISELY. Since people will not use common sense, I think retractables should just NOT exist... Yes, it's a nice idea. Yes, I've used one before. But if people aren't going to use them appropriately, then they don't need to use one at all. Just today at work a lady had a puppy on a retractable leash and let it go up to these older ladies. The puppy circled around them and tangled their legs. Sure, it's a puppy that weighs no more than 10lbs. But imagine if it were a large breed dog, over 60lbs, or even over 100lbs! That dog would knock you on your butt if it tangled you up in the cord!
Like I said, I used a retractable. But I used common sense.
When I go out (stores, parks, festivals, dog events/competitions, etc.) I use a lead that is appropriate - 4ft-6ft is normal, or a trafffic lead which can be as short as a ruler. When I am in the yard, or in a giant field, or the beach, or a spacious area where I don't trust them off leash, I use the retractable. Fortunately Sammy and Motley do not need to use a retractable anymore because they have a good recall.
Plus they are very responsive to my commands in general, so if they saw something they wanted to go after, I can call them back in a split second and get them to leave the target alone. This means I don't need to worry about ever being in a situation where they will hit the end of the lead and break it. Obviously if you have a more rambunctious dog, or a dog with a bigger prey drive, you would want to use a retractable at your own risk because they can and WILL break if a strong enough forces pull against it.
I would not use a retractable for training. You need control of your dog, and a retractable does not give you that control. I never actually taught my dogs "loose leash walking," but I taught them the "heel" command while on a 4ft - 6ft lead. Now when they are off-leash, I can make them heel as opposed to running ahead of me, behind me, or all around/wherever they feel like running...
The way I see it is this; if you can't control your dog in new environments, I would HATE to see how they are in your house... Good grief!