The dog has a tapeworm.
You know how you find out such a thing? You notice your dog munching her ass on a regular basis and so take a look, only to find a half inch white worm thing wiggling around in the general vicinity.
All together now: EWWW! ICK! BLAH! GAG! WOGGA WOGGA!
Off went my dear sweet husband to seek out a cure. Luckily he found an OTC drug so we don’t have to pay a vet and THEN pay for meds.
And my gift to all of you? There will be no photos associated with this post.
You may throw rose petals at my feet in thanks.