I'm not too sure, however at least for Orangutans they're probably smart enough to deal with them when they get rambunctious. Though otters aren't as outwardly aggressive as the larger weasels but definitely would keep smaller less cunning animals away.
I wonder why some zoos put them with other animals like orangutans, given otters still being weasels can get pretty nasty.
I'm not too sure, however at least for Orangutans they're probably smart enough to deal with them when they get rambunctious. Though otters aren't as outwardly aggressive as the larger weasels but definitely would keep smaller less cunning animals away.