Depends on the dog.
Some with false pregnancies have milk and no pups.
Some a week or more before pups
Some after they have the pups
In rare cases, milk doesn't come in. That means a lot of work, round the clock for the breeder.
Remember, pups are way better and getting milk out than people. She may have milk and you can't express any.
She should start producing milk approximately 12-24 hours before she has her puppies, however it can be different with other dogs
Immediately after the puppies are born.
