Jack Russell Rate Terrier Mix Scooting Her Butt Across The Floor, Can You Help?

She may be using the floor to wipe away any remaining feces.
Perhaps leave her outside a bit longer when she completes her business. Dogs also have anal glands that can & do become blocked.
(something you can assist her with). As suggested another possibility is worms,however you may notice this in her stool some worms appear as rice,while others resemble spaghetti noodles.Be prepared to collect a stool sample for your vet.

Take  to your vet --- could be anal gland needs to be popped. Look it up and it'll explain to you what exactly it is.it happens to small dogs. It's not a bad thing but you DO have to get it takin care of A.S.A.P.  Is VERY uncomfotable for your dog,     OR she can have her period.    Go to vet.