You are a good dog mom to be thinking about this!

I have bichons, prone to collapsed trachea, we always use a harness on bichons. My girl Tasha is a puppy mill rescue. When she first got here, she would easily spook and just escape and run. Thank goodness she'd run home!

I found the Rope n Go and love it. This is the only harness she was not able to escape from:
http://www.ubraidit.com/supplies-thumbs.php?cat=81

With time and training, she has calmed down quite a bit. She's been to lots of classes, walks in parks, things to socialize her with dogs and people, as well as just get used to the world. For the past 6 months, I've also used a Walkeez with her. She has not escaped from it, BUT I want to emphasize that she's been with me 3 years and calmed down plenty in that time. http://www.cleanrun.com/index.cfm?fu...roduct_id=1699

I highly recommend you start with the Rope N Go for a "Houdini dog!"