I wish I could help you with that, but after spending 8 years, and thousands of dollars on dog trainers and dog behaviorists, I've come to the conclusion that some dogs are just aggressive towards those that aren't in their "pack". My own german shepherd will submit as long as I'm 100% aware of him and in control. I wouldn't trust him outside of my sight for a minute with a strange dog.

If you meet them on the street or in the park, while walking towards them if you feel your dog is acting up turn around and walk away keep doing this same drill.If this dosen't work watch "its me or the dog" on animal planet and you can see it done, its amazing what that lady can do with dogs

fear in people invokes fear in animals... they sense fear better than we do in some cases so when a person is afraid the animal thinks it is because the person will attack and fears repercussions from the possible acts and will sometimes act first...

You may need to look into getting some professional help for this dog. First off, if she is healthy, of a good weight and over six months of age...GET HER SPAYED NOW. She doesn't need to reproduce this temperament, she doesn't need to contribute to the over population of dogs who are needing a forever home...AND you'll help her NOT GET breast cancer and also some other reproductive cancers too. This problem has no QUICK FIX to it. With out watching her in action it's hard to pinpoint what the actual cause is in her behaviors. If you have not bothered to train her to be really supper spot on with her basic obedience...START NOW! She should respond to your commands for Come, Sit, Stay, Lay Down, Back up, Go to...the door, your bed, the crate... Get off, Get down, leave it, drop it. These are basic commands that ALL DOGS should be capable and willing to do. Training WITH POSITIVE REINFORCEMENT...(+R) not only gives your dog acceptable behaviors to do, when THEY are about to make BAD or Unacceptable decisions of their own...it also builds confidence and self-esteem... Because the dog learns that doing as asked EARNS THEM treats, a favorite toy (only used for training rewards) and always lots of praise, rubs and petting...they learn that good behaviors are a lot more fun and rewarding than bad behaviors! Training gives you acceptable behaviors to ask for when your dog is about to make a bad choice in behaviors...it adds to your bond, it creates accountability between you and the animal...it helps create trust between you and shows the dog that YOUR IDEAS ARE USUALLY BETTER AND MORE FUN. (because the dog is rewarded for doing what you say!) Your girl may need a course of NILIF...(Nothing In Life Is Free) this means NOTHING she needs or wants...food, affection, playtime, walks, going out for potty...is given to her...without her first doing (successfully) a command given to her by YOU or anyone else providing for her needs. When she asks to go outside, she has to sit before you open the door. When it's dinner time...she has to lay down before you will place her bowl, to be petted, she must sit first...and so on. It sounds a bit harsh...but in reality it is setting her up to do two things...RESPECT WHAT YOU SAY...and EARN ALMOST CONSTANT REWARDS!!!! = FUN! I have a dear friend with a wonderful doggie girl who also has this problem...however it is entirely limited to other dogs...NEVER to people...SOME dogs Spring loves with all of her heart...others clearly she would like to bite off their heads and chit down their necks...and there is no rhyme or reason to it..nothing that links the ones she loves with the ones she hates..no clues at all...it's like a snap decision on the dog's part..no pun intended! "YOU I love and You..must die!" It's frustrating at best because her owner lives in an apartment and so must walk her dog several times throughout the day and evening (when she's home from work) for her potty needs! This dog is pretty much under constant training and behavior modification in an attempt to support her NOT doing the wrong behavior. If she spies a dog and starts to growl..her owner then asks her to LEAVE IT...if the dog slows or stops growling...even for a moment...she is REWARDED FOR STOPPING the undesired/wrong behavior...if she does NOT stop or even pause and try to stop herself...SHE IS REMOVED from the area. Behavior modification means that when the animal does a correct behavior it is REWARDED...when they do not..THE FUN ACTIVITY STOPS IMMEDIATELY. Yelling won't fix it. And if the dog's prey drive is that over developed, removing it may not have an impact mentally on the animal..it depends upon how "wound up" the animal is at the moment. What really concerns me with YOUR dog..is that the behavior is becoming linked to other HUMANS...it is about 500% UNACCEPTABLE for a Companion Animal to do. YOU have GOT TO NIP THIS PROBLEM ASAP. If you are unable to help her understand that HUMANS do not fall in the same category as other dogs...then you are courting a law suit when she bits someone...and also the possibility that you'll be forced to have her put to sleep or kept in your house, on your property with a fence AND her on a leash..never allowed outside with out YOU or someone who can control her even in a fenced in area on your property... Get help if you need to...and don't just look for a Dog Trainer...look for a trainer who is ALSO a Behaviorist and one who is familiar with NILIF...AND who uses +R training...you do NOT want to use yelling, or negative training methods on this dog...(or any animal for that matter, not at anytime for any reason..but especially not on one that is already being aggressive). Best of luck...it may be a very long process...try not to give up and always remember SAFETY FIRST FOR YOUR DOG, AND ANYONE YOUR DOG HAS ACCESS TO!

ask your vet about it

she is very protective of her territory.