Paritee's BFAV was in unofficial updates for a looong time, and is now not needed for new animals. The latter means it simply won't be updated again at all.
What to do about your current animals:
1: obsessively track other updates on Nexus and other mod sites. A few animals have popped up.
2: read through the wiki info on converting, there's a whole wiki section. If the description doesn't make sense to you or you work better with example code...
3: grab one of the new animals mods and crib from its code to update your beasties. If it's a beastie with open permissions you can even publish the results, if only in the unofficial thread here on the forum.