I wanted to post this video on training your dog to "Leave It"
[ame="https://www.youtube.com/watch?v=pEeS2dPpPtA"]Leave it part 1 - YouTube[/ame]
My personal preference when training this is to NEVER reward the dog with the treat that is actually in your hand. Treat with a different (higher value) treat from the other hand. This helps reinforce that the item you are telling them to "leave" is never to go in their mouth.
Then, you make your birds something to "leave it". I was lucky enough to have had my dogs already when we brought birds home, and they already had strong leave it commands. After the birds were comfortable enough to meet the dogs, the dogs were told leave it when presented with the birds.
Obviously no matter how good your dog(s) is, you never want to leave them alone together. Even a dog with zero desire to hurt your bird can step on it by accident, or just be having a bad day. It can help give you some peace of mind, though, to know that your dog has an idea of what you expect.
My daughter's bird (the sun conure), in particular, seems to think that flying and landing on a dog is a fabulous idea. If he's heading in that direction and I'm not going to be able to scoop him out of the air before he gets there, the dogs get told "leave it" again and wait patiently until I retrieve the bird from wherever he decided to land -.-
I always, always give the dogs a treat when they give me a chance to reinforce them for being sweet around the birds.