In September I was asked to emergency foster a dog who we then ended up deciding to adopt. He is a small to medium breed but he is so strong and pulls like a lunatic on the lead which unfortunately meant that not only was he choking himself when we went for a walk but that it was in no way a pleasure for me to walk him either as I was constantly stopping or having to pull him back. I purchased a Beaphar gentle leader to help with this.
The leader is made of a pretty tough lead type material and it comes in various sizes based on the size of your dog. It is important you get this right as they wear the leader over their snout and comfort is obviously important as well as making sure the fit offers you the most control.
The leader fits over the dogs snout and then fastens behind their head. Under the section that fits under the dogs snout there is a metal hoop and it is here you attach your lead. Dogs tend to have a natural urge to pull against anything on their neck but the lead being attached under the snout means you have total control of the dogs head and as such can lead them this way. Having the lead attached under the snout also means that it isn't particularly comfortable or possible for the dog to seriously pull against it.
Since we have had the gentle leader we have learned to enjoy walks again. The experience is so much better as he will walk beside me or slightly in front of me without pulling. It is great for training too as you can reward your dog for walking "nicely" and give them treats so the positive reinforcement comes as they walk to heel and eventually you can get rid of the leader and the dog should still walk nicely.
The only issues I have found with the leader is it can rub at the fur around the snout so Buddy had an odd shorter patch on his face, it has frayed slightly in some places too but it is still perfectly functional. Another issue is people can mistake it for a muzzle and avoid the dog which for my dog is an issue as he loves everyone and every thing!
This leader cost me around £6 from ebay and for the joy it brought back to walking it is thoroughly recommended.
Gentle Leader Anti-Pulling Strap is the easy way to train your dog not to pull at the lead Comprehensive training instructions are included.