Introducing puppy to older dog

Question
Hi, I had read many articles and tips on how to introduce a new puppy(toy
poodle- male - now 4months old) to an older dog(westie - female - 2years
old) and have followed instructions on how it should be done.

It has been two months now and their relationship seems to go up and down
all the time, mainly due to older dog being aggressive to the puppy.  

I understand how they need to work out their rank/peck order, but it seems
to me maybe angel(westie) is struggling to establish her top dog position.
Although, the puppy does seems to get scared when angel gets more
aggressive sometimes.

And I also realise a lot of the times when ox(poodle) is trying to play with
angel, she doesnt seems to get the idea. For example, when I take them to
the park to play, angel always end up chaseing ox and use her teeth(although
not actually bite) and push and growl on top of ox until he gets little scared
and walk away.  I think it could due to the fact that angel has never really
social with other dogs. If this is the case, how can I make her understand the
concept of playing with other dogs?

I see whenever they're playing ox is wiggling is tail like theres no tomorrow
but on the other hand, angel's tail is either tuck under between or more often
than not, pointing straight up with her ears also goes flat and points
backwards, which seems to me that it only happens when shes angry and
getting aggressive. How can I change this?

Little bit long winded and not the most constructive email but hopefully you
can help me. Many thanks

Chris  

Answer
It may be she doesn't want to play with him or she is trying to tell him he is biting too hard.  Many older dogs don't want to play puppy biting games, and if they do, they expect the puppy to regulate how it bites.  If he doesn't get it before long, you have have to start teaching him to leave her alone just like other forbidden chew toys.  

As soon as he focuses on her, give him a sharp ''Ah, ah, ah!'', and offer him an acceptable chew toy.