I must admit that I didn't read the discussion that Lee linked to. So what I said above, is just my own uninformed assessment of the situation. I suppose I can't be too far off, though.
The right file for each animation is very hard to find, and very few people know how to deal with them. Really, VERY FEW. I know of only one modder who did an acceptable animation job once, being @NixNivis if I'm not mistaken. And even that was, according to her own posts about it, quite a complicated task that took her a long time to get right.
When I used the word*impossible* in my previous message, I wasn't joking. The Sims 2 has existed for more than a decade now, and of all the modders and creators that exist out there - *including* all those incredibly skilled masters such as Chris Hatch, TwoJeffs, Pescado, Squinge, Inge, and anyone else you can imagine - not even ONE has succeeded in properly cloning the skunk as a pet yet. And that isn't for lack of requests, because you're not the only one who wants one. I've seen such requests on MTS, PBK and Simbology as well, and the answer has always been the same: "sorry, but that's impossible!"
Ok, maybe not exactly impossible, but it would be so incredibly much work that nobody wants to try. Me? I would have loved to try, but I only know about code. Not about graphics, animations, sounds and all that other stuff. So I'm afraid that it's never ever happening, sorry!