I know the vets will pull them out around 6 months if their having problems. So I guess around that age, but unfortunately I haven't been able to find any of Seiah's. As far as hurting them I assume that it's annoying but probably the same as what we go through.
Cooper lost all his baby teeth by the time he was about 6 months old. It didn't seem to bother him much .. with the exception of me grabbing them before he could eat them (they usually just swallow them). I think I was able to grab up almost all of them for his baby book.
Vida only lost two of her baby teeth. That wasn't until she was over a year old. The vet wants to pull the rest out, but I can't really afford it. He says that when she is older she won't be able to eat very well. I will have to have them pulled out soon.
chiwi looks like a shark. she is going to have to have some removed. i'll get it done next month with her spay. however, i just checked her mouth and some are wiggly, even though the adult teeth have started growing in the baby teeth are wiggling so i think there's a chance of some of them coming out on their own. i'm not sure how puppy teeth work. my pit had no problems losing his puppy teeth and his adult teeth came in real well.