I dont know the reasons for the birth defects, but From inside the womb, you can see that the embryos of a pup are about the size of a pea when they're 20 days old. By day 30, the embryos are the size of a grape and the puppies have beating hearts. As the puppies develop, their intestines grow outside the body because there's not enough room inside. As the puppies get bigger, the intestines slowly move into their abdomens. but some times theres a problem and they dont go in, most likely the pup will die before or after birth. It just happens its a birth defect |