A phantom pregnancy is an odd thing to occur and one of the reasons my husband likes to shake his head and say “dogs are weird”. Of course humans can have phantom pregnancies too, but my husband just rolls his eyes when I point that out.
A phantom pregnancy is when a female comes into season, does not get pregnant (for any reason, she might not have even had any contact with a male, much less have been intentionally bred) but the bitch’s body seems to believe she is in-whelp (pregnant).
During a phantom pregnancy the bitch shows all the normal signs of being in-whelp. She gains weight, acts hormonal, eats like a wolf and even her teats enlarge and her vulva swells. Her abdomen will enlarge but the imaginary puppies cannot be felt upon manual examination nor can they be seen on an ultrasound or an x-ray.
In general they resolve on their own and require no treatment. Sometimes a bitch will phantom-whelp and begin taking care of her favorite stuffed toys, too. It is an oddity that is more common in larger dogs than small dogs (or so I’m told) and can happen to regular, non breeding pets as well.