its very rare that an adult dog will do any major harm to a pup, put in its place, yes, sometimes even draw blood, yes but major harm, no. pups have an inbuilt defense they squeel like pigs this is the ultimate submision in dog talk. ive always chucked pups in with both older dogs and bitches and had no major issues infact the last one is still in with his sire over 5 years later
I know what your saying Paulus and you are right that the pup does squeal like a pig, she only has to have a little growl and tap him with her paw and he runs off squealing. He soon comes running back though.