Check for Mastitis Keep an eye on her mammary glands. Most dogs will do just fine, but if she develops mastitis, it can be life-threatening for both her and the puppies.

“Phantom pregnancy in dogs, also called pseudopregnancy, is a hormonal condition where a non-pregnant female exhibits signs of pregnancy such as nesting, swollen mammary glands, milk production ...

Symptoms include swollen mammary glands and milk production, nesting behavior, low energy, reduced appetite, and even a swollen tummy in extreme cases.

If multiple lumps are present, then a whole chain of mammary glands may need to be removed - this is called a mammary strip. A dog may also need chemotherapy alongside surgical removal.