Here's why:
* Pregnancy and Delivery: A dog's pregnancy lasts about 63 days. Once the puppies are born, the pregnancy is over.
* Physiological Changes: The dog's body undergoes significant changes during and after labor. The uterus contracts to expel the puppies and placenta, and then begins to shrink back to its normal size.
* Multiple Births: While dogs can have large litters, all the puppies are born during a single labor period.
If a dog seems to be having more puppies after the initial delivery, there could be other issues:
* Retained Placenta: This is a serious medical condition where part of the placenta remains in the uterus. It can lead to infection and require veterinary attention.
* Complications: In rare cases, a dog might experience complications like a uterine torsion (twisting of the uterus), which could delay the delivery of some puppies.
Important Note: If you're concerned about a dog that has given birth, it's crucial to consult with a veterinarian immediately. They can assess the situation and provide appropriate care for both the mother and puppies.