I need help
I have a 4month old male lab and he's amazing when me and my partner are together and amazing when its just the boys but if its just me and him he bites,growl's,barks and it is a stressful and horrible situation to the point I dont want to be alone with him. I find myself getting very upset and I know it will but a strain on my relationship as my partner adores him as do I but I'm at the end of my tether . Please help I'm desperate xx

http://forum.champdogs.co.uk/topic_show.pl?tid=147294
this may help

I know exactly how you feel!  My 4 month old pup has been a bit of a nightmare, jumping up biting and ripping my clothes.  I did a lot of "googling" the problem and found that it really helped me to see that it is a very common problem and I was not alone.  There is a lot of good advice both on this forum and on others on how to deal with it and I think you have to find the one that works bestfor you and your pup. What has worked for me is turning my back on him, folding my arms and saying STOP in a firm voice.  It does take a few weeks of being consistent but it is getting through to him and now he will stop almost at once.

There is light at the end of the tunnel (i hope).  Everyone says it will pass, but I know how stressful it can be  (I have been in tears ) and it does seem to take forever, but be reassured it isnt just your pup that does these things .

Time out works well for two reasons, 1, the pup ends up alone and 2, the fun stops. So I pick puppy up without a word and place in another room/outside/whatever works (NOT into a pen if that's used for sleeping etc. its not for punishment) I give it 5 mins and let back in by which time the puppy should have calmed down. If the biting continues then another 5 min time out. It does eventually sink into that butterfly puppy brain that biting and growling result in time alone. Its worked well for me over many years. Its not a quick fix and need to be fair and consistent.
Aileen

I'd totally agree with Aileen much as actually I'd get up, say No Biting!, take the puppy out to empty and then back to is crate with some puppy biscuits.   In the hope that this isn't making the crate a form of punishment.  Quite often the puppy is getting overtired when he gets silly like this and after a bit of complaining, if left alone, he will settle down for a nap.   The bottom line must be he learns there are consequences for actions, good or bad but especially bad!      And with mine at any rate, a brief time out isn't as effective as a longer time out - dogs hate being ignored, so ignore him.

My flat coat was exactly like this up to the point my husband came home one evening to find me in tears and I thought i was going to have to take her back to the breeder as she was uncontrollable and aggressive, biting and growling at me all the time. Never had a puppy act in this way and was at my wits end. What actually stopped it was when she was growling and trying to snap at me as I was sitting on the sofa, I just lost it and barked very loudly at her. I don't know which one of us was the most surprised. She never did it again after that and she is the softest, gentlest dog you could ever meet. No one ever believes me when I tell them she was a horror as a pup. I think she was just pushing the boundaries and when I barked at her she realised that was one line not to cross again. I don't recommend you try this as it was an instinctive response on my part and not planned. When your pup does this I would walk away and leave the room and close the door behind you, I agree with the other posters that puppies hate to be ignored. Take heart it will pass and you will have a lovely dog who will adore you.