Regardless of the breed, if the dog was aggressive and out of control with no sign of its owners in sight then it should absolutely be reported. That type of irresponsible dog ownership should not be tolerated.
(I say regardless of the breed because there are dogs that can be mistaken for Pit Bulls - our first dog, Luke, was a Staffie / Lab cross and could easily have been taken for a Pit Bull by those that didn't know better)
On a positive note I doubt that there is any real danger to your toddler.
Contrary to popular belief, even poorly trained dogs don't roam around savaging small children. A dog may act aggressively to another dog if it perceives it to be encroaching on its territory, but it's highly unlikely to launch into an unprovoked attack on a human.
Having said that, staying away from the woods for a while until you know what's happening isn't a bad idea.
If you do ever find yourself in a situation where you feel threatened by a dog, stay calm and maintain an aura of confidence and control.
If your toddler is with you, move him behind you so that you're stood between him and the dog. Don't panic, shout and scream or try to run away - that's likely to agitate the dog even more.
I'd also strongly advise against responding with aggression. If you start waving a stick or pole at the dog, a large, strong breed will take the stick away from you and will very likely respond with further aggression.
If the dog is bounding toward you stand your ground and stay calm - and once the dog is stationary you can back away slowly avoiding any sharp or abrupt movements.
If you feel confident enough you could even try a simple command like "back" or "down" . . . it's the tone of your voice rather than the words themselves that the dog is most likely to respond to, so even if it doesn't know the commands you may get a result.
And remember that some dogs are just exuberant and excitable (and possibly poorly trained) - 99% of dogs that may come bounding up to you are probably not doing so with the intent of attacking.
