other dog aggression in 8 month old boxer

Question
My 8 month old boxer did not show other dog aggression until she was attacked by a rottweiler at the dog park.  Now she barks, snaps and fights with other dogs that she meets if they sniff and get in her face too much.  How do I solve this problem so I can trust her around other dogs? I would like to continue to walk her at the dog park and let her off lead at some point without her getting in a fight.

Answer
It's best to have a qualified behaviorist evaluate her to see in person what she's doing, as we often miss signs and signals our dogs give us that could help us prevent issues before they arise - a behaviorist is skilled at seeing those things and can help you do so, as well.  From what you've written, it sounds as if she's fearful and reactive since her altercation with the Rottweiler, but that may just be a coincidence as she's also entering adolescence, which is the age of testing limits.

An important thing is to be aware of your reaction to other dogs - typically once our dogs have been in a fight, we tend to tense up when we see another dog coming, which travels right down the leash to our dog, who then thinks the approaching dog is a threat.  So be sure you stay calm and relaxed when other dogs approach.  You can also work on desensitization and counter-condition, so that she learns to associate other dogs with Good Things:

http://www.hollysden.com/fighting-fire-1.htm

You should be doing obedience training with her as well, if you aren't already.  The Nothing In Life Is Free protocol (NILIF) helps to establish rules and guidelines, and will help her feel focused and more self-confident:
http://k9deb.com/nilif.htm

Training will also help establish your role as the one who is in charge, and you can help her realize that you're the one who will protect her should the need arise.  A very good article (for any dog owner) is this one:
http://www.livingwithdogs.us/articles/He-just-wants-to-say-hi.pdf

Good luck!