I find it odd that so many people feel so much animosity toward cats. They are much less of a nuisance and much less of a threat to humans.
We live out in the country and raise goats and chickens and also have a couple of horses. When we first got goats, one of our goats was killed by a neighbor dog. Our solution has been to allow our dog to live outside. She is part Aussie (herding) and part Great Pyrenees (guardian). She is definitely much more the guardian than the herder. If we let her know that we do not want a dog on our property, she takes care of the rest. It would be legal for us to shoot the dogs, but Murphy is slightly more humane — unless they stay to fight. She’s only had to fight one dog and it went away after Murphy attacked four times. Usually she just stands the neighbor dogs down. Although she seems so cuddly and friendly, other dogs must find her formidable. She has stood down bull mastiffs that were larger than her even though there were two of them.
When I run, it’s a different story. Few people contain their dogs in the country and I’m bound to pass some place that has dogs.
For the aggressive dogs, I approach aggressively. I run at them if they run into the road. If they try to chase as I run by, I spin around, yell at them, and raise my arms to look bigger. I’ve been known to throw rocks before, but my aim is not too good. Once there were three dogs working together. That time, I was much meeker. I walked until I got clear. One kept trying to circle behind me. That made me nervous. On some occassions, I see an obese dog running out to the road. When that happens, I feel sad that the dog was allowed to become so fat. I do not waste any time on them though. I just pick up the pace a bit and beat them to the edge of their property. They don’t have much chase in them.
I actually have more problems with the friendly dogs. They just want to play or to run with me. Although it is hard for me, I have to make them understand that I do not want their company. I remember throwing a rock at this friendly, not-quite-full-grown lab. He wouldn’t leave me until a rock hit his paw. The wounded look he gave me made me feel really bad, but I really believe though that he was safer staying home with a hurt paw.
Good luck dealing with the dogs. In some ways, it is probably harder to deal with the dogs in the city with negligent owners. Normally if I see any owner it’s an owner calling their dogs back to the house. Usually the dogs heed their owners fairly well. It’s sad that no one there will enforce the ordinance at your park. Unfortunately it will probably take someone getting seriously hurt for them to change their policy.