Why is my red nose pitbull agressive towards other dogs?

She needs a lot of exercise to help curb that behavior. Try taking her on a long walk before the dog park. She is probably going into the dog park in an excited dominant state and she needs to be calm submissive state before entering the park. Please do not stop socializing her because that will only worsen any issues she has. She is still learning and growing at 1 1/2 years old. My dog Dude is the same age and we are working on the same thing. I correct his behavior every time he starts to get aggressive with a swift "Hey" or "No Dude" and he stops. But I have to remind him often.