
In my opinion, breeding from a 15 year old bitch, is outrageous and downright cruel!

I don't doubt it's true, though. Nature is very practical/cruel. Bitches can have litters all their lives, not like us women who stop reproducing at an apropriate age. What happens when an older bitch is in whelp/lactates, is that all she has will go to the pups, leaving her totally drained herself. Of course she will hopefully regrain her strength when the pups leave, but it will still have taken it's toll, having a litter. Her life will be shortened, for sure.
If a bitch has had only one or two small litters, or is of a breed that ages slowly, breeding from a bitch over 8 years of age might be OK. Otherwise I'd say my answer to the original question is "no". No reasons other than selfish ones, to breed from a bitch that's over 8 years old.
Karen