Im soo sorry this happened to you! And i am soo Glad that your dog is recovering.
I dont want to start a debate, And i dont mean to offend. But please dont blame the attack on the fact that the dog is a pittbull. PLEASE dont. Im not trying to lecture, But the reason there have been alot of pittbull attacks is definatly the owners fault. Pitts are very loving and caring animals, very eager to please and what not. But they are indeed terriers, And MOST people buy these dogs and dont do ANYTHING with them as far as training, And we all should know how terriers need to be taght manners

Most get one and will accually teach the dog to be viscious because they think it is in some way cool to make a pittbull a mean and scary dog. .
Sounds like They got the dog to be cool and in someway impower themselves by having a scary dog, and these types of people will indeed not teach the dog manners, obediance and will even try to make the dog mean and train it to bark and gorwl at people. And by the sounds of it, These people arent concered about there dog much considering they let him roam.
He may even be used for Dog fighting. were his ears cropped? they are cropped so they arent as vulnerable to its aponent and the aponent cant bite them by the ears and pull them down.
So my qeustion is, Was the dogs ears cropped? Because if so, He could very well be used for fighting, and that may be why he tore off after your little one. And if he just wasnt socialized and taught anything, that is also not his fault, but his owners. Or maybe his owners thought he would look better with cropped ears. I dunno. But een this simple sign could mean sooo soo much.
BY the sounds of it. It isnt the dogs fault. Dont blame the breed, blame the owners. Again i dont know if anybody hear accually beleives the crapola about pitts being mean forocious dogs. And honestly, if you do i pitty you. BUt dont blame the breed.