Why is my dog so aggressive during lactation (nursing)?

A dog becoming aggressive after giving birth is mainly driven by her instinct to protect her puppies. After delivery, the mother’s maternal drive kicks in, and to defend her young she becomes unusually fierce. During this time, even if the owner touches a puppy, the mother may attack, so we don’t recommend casually handling the pups to avoid getting hurt.

If you need to clean the puppies, lure the mother away first. Remember to wear gloves before touching them, to avoid transferring unfamiliar scents that could make the mother fail to recognize her own puppies.