Chizzie and Chattie both let their 14 week old pups nurse -- but only for a minute or two at a time and the pups only nursed once or twice a day at that point.
I find it hard to believe that 14 week old puppies that were being fed puppy food would be eager nursers. Life is just to full of interesting things to do to slow down enough to nurse enough for their main source of nutrition. Something just doesn't sound right about that. It breaks my heart knowing that dogs, cats and other pets are being sold like cattle.