Private Training or Group Training?
I've been having some issues with Jazz, 2 years old, that I've been unsuccessful in resolving. I do NILIF, but it doesn't seem to help with the issues were having. Since he was about 1.5 years old I noticed he became very dominant toward other dogs. He has begun displaying inappropriate behaviour toward other dogs recently which seems to be increasing in frequency and I believe I need some professional help. I believe this to be dominance based, not fear based. Here are some specific examples of what concerns me:
1. When I walk Jazz and my female Bunny they play roughly but not inappropriately. It's balanced and one is not overpowering the other. When we walk with my friend and her male, Jazz's play becomes aggressive and he goes after Bunny. He will bite her and take her down. He seems to still be playing but it's way too aggressive. My friend's dog joins in and the two team up on her. I break this up and leash Jazz, and Bunny and my friend's dog play fine together.
2. Jazz has displayed inappropriate acts of aggression recently toward some dogs for no reason that I can tell. I DO NOT let him off leash if other dogs are present with the exception of my friend's dog because they have grown up together). For example, the first act which has really upset me occurred a couple of weeks ago. Another tenant has a 5 month old German Shepherd pup. Jazz has met this dog a couple of times in the past and they played together while on leash. Since they got along fine in the past we let them sniff. Everything was fine for the first 10 seconds and then out of nowhere Jazz turned on the pup. He did not bite the pup but I was able to pull him back so I don't know if he would have. I didn't see the pup do anything to set Jazz off.
He's also begun showing aggression toward some of his dog "friends". One of his friends bumped into him from behind and he turned and snarled at her.
He's never bitten a dog but I don't want it to get to that point. So far, it seems to be all sounds and posturing, no biting. For the safety of others though, I no longer allow him to be off leash if any other dogs besides Bunny and my friend's dog are present. I no longer allow him to meet other dogs on leash because I don't trust him now after the incidents I just mentioned. There have been a few other incidents similar to the two I just mentioned so this isn't just a fluke.
He is not a handler soft dog like my female. Jazz has a very hard temperament. I'm not sure if that makes a difference in how I should correct him but I thought I'd mention it.
I'm wondering if private training or group training would be best for him? The training school I've taken him to in the past offers both types of classes. They use positive reinforcement training only. This seems to be popular but I'm a little skeptical because that's what we've done since the beginning and yet I find myself in this situation. He's done puppy kindergarten, basic obedience, CGC prep course (passed CGC), and intro to Agility.
Thanks for any advice on how I should proceed.
Jazz, Shiloh Shepherd, 5 yrs old, CGC HIC
Bunny, GSD X, 7.5 years old