I've had a similar problem with my youngest bitch, but
caused by RingCraft :( She gets so excited that she almost turns herself inside-out wagging her tail - which has bled from catching the tip on a wall at one show

And when she finally calms down she shakes all over with sheer excitement and exhuberance :(
Thing is, you want them to enjoy it, as it should be fun for them too, but when they are
that excited it stops being fun for us and them :(
I have found
Calm Down herbal blend brilliant for her. It doesn't 'dope' her, and she still has her lovely sparkle, bounce and attitude, but without the shaking and 'over the top' silliness :) I'm hoping that with time she'll calm down, she's still very much like a pup, even at almost 2 years :D