User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-101.160.192.90-20130602025323/@comment-4543229-20130602153232

The only way I have seen elders limp is in download quests, because in those, they can't scape like in regular quests.

They even go to sleep to recover health, and Teostra gains his horns back after sleep. Dunno if it's a bug, or if they intentionally do it, meaning he CAN regenerate parts.