That is not the only pet issue mate.. In Morin Khur if you attempt to go up the wooden stairs with a pet (at least bear) while riding a horse, the pet will 100% time get somehow stuck under the floor or the mountain side, even though that should be place where it cannot go to. Multiple reports about this. This is why i walk those stairs these days, also saw other people's pets stuck in the same location. Also the east bullhead tunnel gets pets stuck in the middle, you cannot go through it with them. Also Tindrem sewers if you try to enter from inside the city pets refuse to go down after the first stairs.. And the list goes on..