1
general::
Phrase(s): rub someone or an animal down
to stroke or massage someone or an animal, for muscular well-being. • Sam rubbed his horse down after his ride. • He rubbed down his horse.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Briskly rub the body, as in a massage. For example, The trainer rubs down marathon runners, or That horse needs rubbing down. This expression was first used (and still is) for rubbing away dust and sweat from a horse. [Late 1600s]
American Heritage Idioms