I agree its not just the indoor pets who suffer. I have seen people moving horses in horse boxes away from the area where one of our local organised firework displays is held. We are lucky to live out in the sticks and not close to any displays or fireworks at home, but I still go out and check on our pony and goats a few times during the evening - after all, their hearing is far more sensitive than ours.
Our neighbours had a New Years Eve party once with fireworks, without advising us in advance, and our animals were terrified. I spent over half an hour in the rain trying to comfort them! I wish the sale of fireworks for domestic use could be banned once and for all.
Its not just
Hedgehogs in fires either. I remember going to a large display once and when the fire was lit, dozens of little mice started running through the crowd - obviously taken shelter in the pre-built fire pile.