4 month old puppy fearful of dogs/growls and tries to bite me.

Question
I have a 4 month old golden retriever puppy, Fiona.  Fiona has always been a
very sweet, submissive animal, and I love her to death.  However, ever since
she was young (I got her at 7.5 weeks from an extremely reputable breeder)
she has been scared of dogs.  I started her in a puppy k-g class when she
was 9 weeks, and she expressed very submissive behavior (tail tucking, ears
flat, submissive peeing), and never engaged in any sort of interaction with the
other puppies.  Since then I have been trying very hard to socialize her the
right way - play dates with dogs I know, puppy "play times", where she's
mixed in with other puppies and allowed free roam of an area - but she just
doesn't feel comfortable around other dogs.  I am worried that one of these
days her fear may turn into aggression, so I want to really make sure that she
is comfortable around dogs and doesn't feel the need to be so submissive.  
There are some dogs she has no problems with - older dogs and calmer dogs
.  Fiona will always try to play with these dogs, even though they have no
interest in her.  So she isn't scared of EVERY dog in the world, just most.

My second problem is a behavioral issue.  I think Fiona doesn't yet understand
that I am alpha of our pack.  I have been doing confidence building exercises
with her like letting her win at tug of war and doing dominance reversal, and
now I wonder if that's gone to her head.  Several time she has growled at me
and bared her teeth when I tried to do something - like clip one of her
toenails (she has been fine with getting her toenails clipped until about a
week ago), take away a raw marrow bone from her, or like last night, when I
tried to pick her up to carry her to bed, she gave me a warning growl.  The
first couple of time when she growled at me, I reacted incorrectly.  I just
stopped what I was doing and let her get her way.  The last 2 times she has
growled at me I have put my hand over her muzzle (I didn't grab her muzzle,
I just put my hand over it), and said, "Fiona, no." in a stern voice, and kept
doing what I was doing.  Is that the correct way to handle it?

Thank you for any suggestions you might have.

-Karla

Answer
Continue introducing her to dogs of all shapes, sizes and temperaments. Some dogs she won't like and some dogs she will. The best thing to do is keep providing her with positive experiences. Some puppies are just too excitable for some shyer dogs, but it's still important that they learn how to deal with them. Remember not to reward her for acting scared by picking her up and comforting her, but if she starts growling or snapping, encourage the other dog to move away. Don't worry too much as long as the other dog does move and she doesn't chase them. Remember that your dog is training the other dog too and extra-rowdy pups sometimes need to get snapped at by another pup to learn manners.

Follow the tips in my article at http://www.thegooddogjournal.com/2009/02/whos-boss-establishing-pack-leadership.... to ensure that she sees you as pack leader. Don't correct growling, instead ignore it. If she learns that growling is bad, she could eventually stop growling and bite instead. You are a very different thing than another dog. Of course you shouldn't abuse her or threaten her, but all you really need to build her confidence with you is act like a strong leader, be gentle but firm and be consistent in her training. Some nervous dogs also respond well to establishing a regular schedule.