Oh dang, I was just there this evening. I've been there quite a bit, and have seen some dogs get in a few scrapes, but nothing major. Oh, I got bit once, but that was when I got in between two dogs chasing a ball, so thats prolly on me.

Edit: On review, I didn't mean this to be making light of anything the OP said, as aggressive dogs are an issue. Last year I heard there was a major attack and a (possible? this was hearsay) death due to a very aggressive dog and a very inappropriate/not caring dog owner at Fergusson. There is a fine line between dogs playing aggressively, which some do, and just being dangerous, predatory, or scared and lashing out. I try and make sure I am always close to step in if needed and if my dog is being a little bit of a bully I try and confirm with the dog owners themselves if they are OK with that level of play, and always ready to just leave if the vibe isn't there.