I have never used it, but have heard lots of people swear by it. Personally, the powder is so fine, I can't imagine it would be good for the dog to accidentally breathe it in. You know, if there was a strong wind or something. Even if there is no wind, when you put it on, small bits of powder probably fly into the air. You just can't see it.
I have used it for fleas before. Last summer I caught some feral kittens and brought them in the house to tame. Well, of course they were infested with fleas and gave them to my dogs. I sprinkled it in my dogs' coats and in the carpet. It works by serrating the exoskeleton and dehydrating the fleas (or any other insect it comes in contact with!) and can take a couple days to kill them. Perhaps I just didn't give it enough time to work but it was more than a few days.
I ended up getting frontline for the dogs. Who knows, it may have helped a lot in the carpet though. I never had a problem with the carpet being infested.
It is dangerous to breathe in when you are applying it. The powder is so fine it will hang in the air for several minutes and you should wear a dust mask when applying it and I would cover your bird's cage too. Once it settles it is very safe. I did not use a dust mask and had a sore throat and swollen lymph nodes after applying it. If you apply it to the dog's coat it would probably be a good idea to do it outside where the wind will sweep it away.