My 10 week old berner will get very aggressive at times when I challenge him on things, ie the other day he was trying to get under a fence to which I didn't allow and he started to nip me at first and then started to growl and bite me very hard when I prevented him from going under the fence, is this a common puppy reaction? He only responds to the yelping that we make if he bites to hard like 5 times out of 10. He will eventually stop bitin hard as the time passes but he has moments of craziness when he just bites way to hard.

Personally I wouldn't call this aggression he is only 10 weeks old. He is doing something he likes he doesn't know you that well yet nor you him and he is frustrated at this person trying to drag him away from something that is such fun. I take it you are taking his collar and pulling him away ? Children will scream and shout and throw tantrums when they are not allowed to do something they feel they should be abe too he is doing the same but in the ony he can react by nipping/biting.

You are building a bond and it is crucial you make him realise he needs to do what is asked but without the teeth.

Firstly not many dogs appreciate being yanked or pulled around especially by the collar and Berners are very sensitive to any harsh treatment. I would find a nice smelly treat, IE, liver (dried) cheese or a favourite he has already then when he starts doing something he shouldn't call him wave the treat under his nose and lure him with it, when he comes away from whatever it is he was doing praise him loads make a fuss and give him the treat.

If you feel you do not want to treat him as much then make things fun and use distraction you may find this means getting down in a play bow position and making silly high pitched noises and calling his name but it is fun and he will think this is much better and I get to roll around for a bit with my dad. There is nothing like a good old floor play with your new Berner puppy it really does build bonds and it is great fun if he starts to get too nippy then calmly get up end the game with a game over then walk away till he is calm again. Initiate play again if and when you want to it all has to be on your terms not his but gently does it with these sensitive happy loving dogs.

You can start this training when he is being good and also slowly desensitise him to you taking his collar. Treat him for things he does that you are happy with him doing or loads of praise whatever works best and with the collar gently touch the collar talking to him all the time till gradually you are able to slip your finger under it and gently lead him by it.

He is very much a baby still and the way you train him now will be what imprints on him in the future.

Thanx for the advice!! He wasn't on a leash he was just in the back yard with me and was halfway under the fence, I was just trying to stop him from going under. I've read Berners don't do well with harsh actions, not that I would do anything like that anyways. I just was concerned that his little freak out may have been a sign of aggression. But he has already improved behavior since the other day. He has been responding well simply to the wot ouch. But thank you very much for responding, it eased my worries!!