I don't think I plan on posting on this anymore... it was not handled correctly at all.
I have two Pitbulls, you should probably do some research before talking about how it was just "Acting like a pitbull". They do not have a high prey drive, it's the same as almost any other breed, and less then retrievers and hunting dogs. They are known for other dog aggression. They have one of the lowest bite rates amongst children, and when temperament tested with cats they will usually only chase/play with the cat.
Has this dog ever been around cats or birds? If not, why the heck was it in an apartment with both? Would you take your bird and cat to the pound and let them in the kennels with dogs you didn't know? Of course not. The situation isn't the breed or the dogs fault, it's the owner for not socializing the dog properly and yours for letting it around your other animals. My dogs have been raised around my birds, and are perfectly fine with them yet I still shut the door to any room with a bird in it at night. It's just asking for trouble. My Pitbulls snuggle with my cats, in fact I have pictures of my cats sleeping in kennels with the dogs.
I can not believe you punched a poor dog for your mistake. Putting your hands on an animal in that situation is never recommended, and you could have gotten yourself severely injured. The golden rule is voice command, then intervene with water, and last you use another object to try to separate the animals. People get mauled yearly for intervening with animal fights and they could always be prevented.
This entire thing was handled incorrectly, and to blame a breed is the biggest cop out ever. People dislike the breeds because they have done 0 research and believe the hype. Then they do stupid things like letting their animals loose with a dog they've never met, putting their face near a dog, letting their kids play with strange dogs, breaking up fights.
I feel bad that this happened but it was 100% preventable, and 100% not handled correctly.