I really wish I had a dog to run with I don't have much information to offer, reading your post I remember seeing a video of Christopher McDougall (the one that wrote "Born to run) running with his 2 dogs - maybe you can find some info on his blog?

And then a friend send me this video:

http://www.pinkbike.com/video/190744/

It's not about running but about biking with a dog, it's so cute