my dog doesnt like other dogs

Question
We adopted a female black lab from a shelter 2 yrs. ago. She is a wonderful family pet with one exception, whenever we are walking her or have to take her for her vet visits she will growl and pull when we get near other dogs. She is so strong it's hard to hang on to her leash even with a prong collar on. Everyone tells us she probubly wasn't socialized when young but what can we do now to get her over this behavior? I can't take her to classes because she almost uncontrollable to hang onto. She is we guess around 5-6 yrs. old She had been turned into the shelter as a stray so we don't have any background on her. My Mom is coming for a visit in July with her little manchestire terrier to stay with us. Any ideas you can give me would be greatly appreciated. Thank you so much, Kris.

Answer
Kris..first of all..GET THE PRONG COLLAR off that dog! It will make her aggressive. Think about how you would feel with something pinching your neck all the time. You need a good trainer. We often get dogs that are like yours in group classes. We have no problems. Look around and find someone that can help you with a regular collar. I am sorry I can not be more help long distance. thanks
Nancy