Shy with people, aggressive with other dogs

[kan888]

Hello, everyone!
I have a 17 week old female Rottie mix (some say she appears purebred, but I don't think so---got her from a puppy rescue organization, so can't be sure.)
I adopted her at 10 weeks.
She is quite shy and reserved with people she doesn't know, though this is improving. On the other hand (or paw) she is becoming aggressive, often growling pretty fiercely and straining at her leash, around other dogs.
We are halfway through puppy classes at PetSmart, and the teacher has given me some helpful hints, and I have also arranged for Kira to have a private lesson next week to just work on "leave it" in relation to her aggressiveness with other dogs.
She plays with our older male dog, who is 3 times her size, and is rough but not hostile with him.
I have raised several puppies, none with apparent Rottweiler genes, and Kira is surely the most challenging! She is smart and beautiful, and can be very sweet, but the aggression concerns me, not to mention that it makes socialization trips around town a bit intense.
Any suggestions or thoughts you may have would be much appreciated. This is a great forum!
Thanks,
Susan

[TrishB]

You're on the right road - continue with the training sessions under professional supervision. Look up other professional trainers; nothing against Petsmart, but I don't believe they go into the higher levels that you'll require her to go to. Try http://www.apdt.com/ to help you find one in your area.

Make "Play Dates" with other Puppies / Owners in your training class. Make a date to meet at a park or on a trail, do picnics, etc. Anything to get her out and about with other people and dogs.

Being consistent is key - whatever the technique it is that you're using, recommended by your trainer, be sure that you're consistent. If anyone else is walking her, be sure that they're handling her in the same way. If you don't trust them to (i.e. your kids, especially if they get distracted playing otherwise), then don't let them walk her without your supervision until this subsides.

If you do a search for "dog aggression" and "socialization puppy", you'll find LOTS of threads that will help you with techniques, do's and don'ts and the “why is she doing this”, type of questions.

Best of luck and let us know how it goes! :) And welcome to the boards - you're going to love it here. :D