My Ig's aren't phased by my 2 African Greys and Cockatoo (even when they reach the 9 decible level). I've put them (practically) snout to beak and the Ig's might give them a tounge flick if they're feeling curious that day. Dogs, however, are a different story.
All 4 of mine are terrified of dogs. . . even very small ones. I don't have a dog but have been know to baby sit the occasional Yorkie or Scottie. The first time the dog approaches their (huge) cage, they do anything from panic & bolt, to just plastering themselves into the walls on the highest perch. They don't eat well until after the dog leaves either. . . even though I make sure the dogs never hang out around their cage but only pass by their cages on the way out for walkies and such. The same behavior holds true whether we're talking about the Ig's being in their inside or outside cage (with the whole back yard around them). I've decided the only dog I'll ever be able to have is a very small on that I'd have to raise from a puppy to not give the Ig's a second look and (hopefully) get them to do the same.
I know this probably isn't what you wanted to hear but, good luck to you.
Rebecca (and the zoo)