If a female dog gave birth to 6 puppies, it is reasonable to assume that at least 6 eggs were released by her ovaries during ovulation. Here’s why:

In dogs, each puppy typically develops from a separate egg that was fertilized by sperm.

Female dogs (bitches) are polytocous, meaning they usually release multiple eggs during a single estrous cycle.

To produce 6 puppies, at least 6 eggs must have been ovulated and successfully fertilized.

However, it’s possible she released more than 6 eggs, but only 6 embryos successfully implanted and developed into puppies.