Actually, I have a different suggestion. At the shelter, we only walk the dogs in the field or take them on outings in our Premier collars. They are great. You can adjust the size and the dogs can't slip out of them. We don't believe in using choke collars. No one has ever escaped one of our Premier collars.

Hmm, I can't find a pic of the collars we use. I'll take a picture of mine tomorrow.

Premier also makes the Gentle Leader which a lot of our staff and volunteers use on their own dogs. They freak some people out who don't know anything about them since a strap goes over the snout. But most people who use them swear by them. They really control leash pullers in a humane way. http://www.gentleleader.com/about/about.cfm