Your best bet is to use interactivity and animations is to use Publish Online (available in CC 2015) or a Fixed Layout EPUB.
Interactive PDF is getting to be an old format and doesn't support animation. Trying to use SWF with a PDF is "problematic" (a kind way of saying "looks like crap"). It's basically a cheap hack and looks like it. And SWF won't work on mobile devices and many people are no longer using Flash.
I am trying to create a drop down menu when you rollover the tab for an interactive PDF
For PDF, this kind of effect/interaction can be created, and you really don't need animation to do it. If the PDF is viewed in full screen, you can use Page Transition effects to create fades and motions. Unless the animation requires some special effect, I can share some PDF examples of drop down menus. I would be interested to see an example of what you are trying to accomplish, is there some where out on the web with this effect?
I agree with Steve. IMO, about the only thing interactive PDF is good for now is forms.
Beyond that, for the type of interactivity you want FXL EPUB or using Publish Online is the better way to go.