Having "aggression" problems with Stryder...

HOME: When Stryder gets all riled up, or frustrated that I'm taking too long... he will just start getting into it with Kiba. It's not regular play, he just kinda goes off on her and more than once recently he'd been doing it a bit too hard and making her yelp.

DOGPARK: Yesturday we went to the dogpark... Stryder was being a bum so I found some toys in the far corner to play with. He was fine playing with me, or with Kiba. If any other dogs came by and just stood next to us watching (like right next to me.. stepping on my foot) he was fine. But any attempt to join in on the fun he'd go after them.

I dont know if its just because he's overstimulated or what.. or if it has anything to do with him not being neutered. This kinda scared me yesturday at the dogpark. It's sooo not like him.. he's the soft cuddly bug that often comes and hides behind me at the dogpark when he's bitten off more than he can chew.

Help? Any ideas?

Sorry, didn't see this till now... Might want to move it to the Training forum, hopefully other trainers will be able to give their input.

Anyway, at home, it sounds like displaced aggression. This is pretty common in dogs - they get frustrated or upset about something, and take out their aggression on the closest thing, sometimes objects, sometimes other animals, sometimes people. This is why more dog bites happen when the dog is hurt, because he is upset and frustrated and just lashes out at whatever is closest, usually a human. The only advice I can give you about this is to try to prevent it from happening - when you see that he's getting frustrated, separate him and Kiba..... try not to let him get so frustrated.... work on some self-control games seperate from Kiba, in training sessions (leave-it, stay, go to bed, etc., and work on variable reinforcement so that he doesn't get a treat every time he does a behavior he knows).

At the dog park: I don't really understand this line: "But any attempt to join in on the fun he'd go after them. " How does he "go after them," does he growl, charge, hackle, jump on them, bite at them, chase them, etc.? I'd like lots of details of exactly what it looks like during the event as well as after - does he stay aroused for a long period of time after, come back to you calmly, continue chasing the other dogs, etc.? And what does the other dog to to "attempt to join in on the fun," jump on him, play bow, run away, growl/bark, etc.?

He'd charges them.. and jump up and bodyslam them (with feet.. think of how a boxer plays) and then comes back to playing.

The other dog was attempting to grab the toy. Stryder was perfectly fine if the dog was standing next to us doing nothing (wanting to get the toy but not doing anything)..