5 month old puppy gone crazy

Question
my 5 month old Black Lab mix girl puppy (will be spayed at 6 months) has
been quite a handful lately. I have been working with her since the day we got
her- at 2 months old. I taught her to sit, lie, stay, and shake on command. I
also have a 4 year old mini-poodle mix. The poodle is completely sweet and
good natured, but ever since we got the puppy, he has had a rough time. The
puppy- her name is Sami- bites the poodle (Auggile) and he responds by
biting back- which excites the puppy, who barks and bites again. When I am
out in the yard with them and see this happen, I rush over and close the
puppy's mouth and say "NO BITE" in a stern voice. It seems to work, so i take
off my hand and she bites me. Now, she doesn't bite hard because she's
learned bite inhibition, but still, she bites and nips. My poodle gets protective
of me and growls at the puppy, exciting the puppy who bites him... so we're
back to square one. I have run out of ideas. I would send her to a trainer, but
right now i don't think i could afford that right now. Please help! The older
this dog gets, it will get harder to control her and if she doesn't learn now,
she will be used to being 'in charge'.

Answer
Young Labs, which I know best, and other puppies tend to very bad about
biting.  You see a litter of them, and all the ones that are awake are biting
another one or themselves.  I am not even sure they realize that when they are
alone, if they quit biting, they would quit being bitten.  At 3 to 4 months
they are getting their adult teeth, and it seems they spend every waking
moment biting or chewing.  One thing you can do at that stage is to knot and wet a piece of cloth.  Then freeze it.  The cooling will soothe the gums.  Only let the puppy have it when you are there to watch it.  I maintain a Lab's favorite chew toy is another
Lab.  Otherwise they settle for any person they can.  They keep hoping to find
one that won't yelp and jerk their hand away, or growl "Bad dog." and clamp
their mouth shut.  Then offer a chew toy.  They keep trying despite hundreds
of corrections.   Another good technique is to quit playing and go away.   Be
sure to praise them when they are playing nice and not biting.

Even as they get older, many dog continue their play biting, possibly males longer than females.  We are seeing quite a bit of it this week between our 11 month old female Lab and the 6 year old male Lab we are keeping for our friend.  As long as both dogs are enjoying it, let them go.  If the older dog isn't interested, give the puppy a sharp ''Ah, ah, ah!'' every time she starts for him.

Continue your obedience training.  It is very important, and you should be able to establish your top dog status without a class or trainer.  See http://www.dogbreedinfo.com./topdogrules.htm

Thank you for planning the responsible step of having her spayed, and thank you for including that info in your question.  .