We have a 4 month old puppy that displays uncontrollable aggression to other dogs. We socialize him at pet stores, horse shows and with kids at every opportunity. I'm concerned because he's going to outweigh me when he's mature and he has already lunged at my friends dog and his teeth nicked me in the thigh when I got in the way.

You can read this to get our definition of socializing. You may see that what you believe is socialization may actually be causing more problems in the long run. We want our puppies to be comfortable but indifferent to people, places, animals...this is all done through keeping the puppy engaged and focused on us and protecting them from potentially scary situations or experiences.

I don't have any recommendations for trainers as we don't have knowledge of the facilities and skill of the trainers in your town. We usually recommend doing the preliminary training yourself anyway, even if you eventually branch out to working with a local trainer or group.

I'd recommend:

Establishing Pack Structure with Your Puppy DVD
The Power of Training Dogs with Markers DVD
The Power of Training Dogs with Food DVD

I'd be working on engagement with this puppy, so he learns that other dogs in the environment only mean good things come from you. At 4 months old, it's important to set him up for success through positive methods. You don't want to correct him or make him worried.

I recommend this free 3-part video by Michael Ellis on fear periods in dogs. It explains how to condition the dog to things that make it nervous:

Part 1 | Part 2 | Part 3

We also have a number of eBooks, which include topics that may help you.

Cindy Rhodes