BAD BREATH

I have 3 dogs and all three have a different problem. Since this would be too long in one message, I'm going to post 3 different messages...My 1. dog is a little Yorkshire Terrier/Chihuaua Mix named Oskar that I just got from the shelter last week. Somebody has burned his back and he was found running around in the streets. Now he seems already much better and I can tell that he likes it here. This little guy is all cute and sweet but he really has very very bad breath. I tried to brush his teeth but he is so little that I was scared to hurt him. And he didn't like it at all. Any ideas what I could try???

Claudia