Holly got over excited when learning figure 8's through my legs too!
Especially when I started to turn it into weaving between my legs, she growls and tries to do it as quick as she can and if we keep doing the trick then she can get into a bit of a state.
And now that she can do the agility weave poles she also finds them extremely stimulating and sometimes growls. If she gets too over the top about it then she starts to make mistakes, the more I try to get her to do them correctly the more excited she gets until I have to stop her and not let her enter the weave poles again until she calms down.
But those are the only tricks that really make her too excited.
Lewis starts to go a bit nuts if I just ask him to "sit", he pants and flicks his head around, if I'm too slow with the treat he starts to drum his paws on the ground and leaps sideways into another sit. Then he slams himself into a "down" without me asking

but he is just a crazy dog in general and gets too excited to learn anything
