Bailey's really enjoying the dog park. She usually finds someone her own size and age to play chase with. Most of the small dogs go to the small dog enclosure, but a few stand around in the big field screaming at the top of their lungs. (pay attention to me!). We've encountered a few bully dogs, but mostly everyone runs away from them. No dog fights.
Yesterday a man with an Italian Spinolla (sic,ph,?) (never heard of the breed) was complaining that his dog was such a wimp and he just wished he'd nip one of the dog's that were chasing and trying to mount his. Well, I think everyone felt that his dog was wonderful, that he was great fun. It was a benefit to have a dog that wouldn't freak and peak. A dog park doesn't need an aggressive, biting dog.
Bailey loved him. They played very well together. And as for the dog that was trying to mount other dogs...his owner said he does that with everyone, including her. Bailey just brushed him off (he'd need a step-ladder in any event), so.... Don't worry, they just want to play not work out world dominance. Be happy that your dog is pleasant and not a problem dog. Believe me, when your dog needs to protect himself, he will. When Bailey gets hurt, she let's the other dog know, but, thankfully, the anger is gone in a minute. I'm glad she doesn't carry a grudge.
Perhaps your park just has an over abundance of violent dogs. Do you have other parks in your city that you can go to. There are definite differences in the ones here. Also, different clientele based on weekday, weekend, end of day, early morning: switch it up, eventually you'll find a group that's best for your dog's temperament. We found weekend afternoons/evenings were the worst for bad dogs/bad owners. Some very aggressive CC's and Rottie X's with oblivious and stupid owners. Best of luck to you.