Dog Aggressive Golden

Question
Hello,
I have a 2.5 year old female golden retriever that I have has since she was a puppy. This past July I boarded the golden and our other dog (a 2year old male Doberman) for a week. While there they participated in doggy daycare. Since returning from vacation my golden has been other dog aggressive at the local dog parks. She shows no signs of aggression on the leash but as soon as she is free she starts fights with or just goes after other dogs (only dogs her size or smaller). I do not even know where to start to correct this behavior because she was never like this before the kennel. I live in a condo with no backyard so the dog park is a fundamental part of her exercise but I cannot take her there anymore. (Side note, the Doberman had no negative behavioral changes)

Please help if you can.

Thank you,
Dana

Answer
Well what usually works is to muzzle your dog for a while,so she can't hurt other dogs,but will realize they aren't going to hurt her either

Another thing you can try is to have her go to someone's yard that you know that has another dog and muzzle both dogs so they can't hurt each other