My girls had 11 pups each in their litters there was no intention to attempt to have large litters and Penny's own mother never had more than 4 in any of the litters she had. Penny was mated a second time, but I wasn't hoping for a repeat. That pregnancy ended with uterine torsion, all pups were lost and mother was lucky to live. I believe having a large litter may have contributed to the torsion but with so little writing on the matter (because it is extremely rare in dogs) I will never know for sure. However with just one mating her daughter Phoebe also went on to have 11 pups. She was unable to feed and hand rearing was a nightmare I would never wish to repeat, but I did not want to risk another mating particularly in view of what happened to Penny.
In these cases I assume that the dogs were mated at just the right time and that they were healthy enough to sustain all embryo until birth, I don't think anyone expects to have such large litters but as with everything sometimes it just happens that way.
