Dogs eat their newborn puppies when they do not recognize the puppies as their own, because the pain from mastitis and suckling provokes aggression, or because a puppy is stillborn or unhealthy. However, cannibalism rarely occurs among canines. Some breeders theorize that cannibalism is an inherited trait that may pass from one litter to the next.
Dogs that give birth through Caesarean sections are less likely to recognize their offspring due to the lack of birth hormones. The high-pitched noises emitted by puppies and their erratic movements often trigger a predator instinct, causing dogs to kill and eat their young.
Another common issue is mastitis, a condition in which the teats become infected or inflamed. If the condition is severe enough, milk production stops entirely, and the entire litter can starve to death in less than 48 hours. To prevent any tragedies during the whelping process, it is necessary to keep the mother as comfortable and stress-free as possible. Some anxious dogs seek to remain close to their owners, while others hide their puppies. Plump, contented puppies indicate that the mother and the litter are both healthy. Puppies should be weighed daily to ensure that they are gaining adequate weight. Owners may need to supplement the diets of any underweight puppies.