"Slut meant female dog once too."

Comments rhhardin, in the "What exactly did Rush Limbaugh apologize for?" post, below. That made me look up "slut" in the Online Etymology Dictionary:

slut

c.1400, "a dirty, slovenly, or untidy woman," probably cognate with dialectal Ger. Schlutt "slovenly woman," dialectal Swed. slata "idle woman, slut," and Du. slodder "slut," but the ultimate origin is doubtful. Chaucer uses sluttish (late 14c.) in reference to the appearance of an untidy man. Also "a kitchen maid, a drudge" (mid-15c.; hard pieces in a bread loaf from imperfect kneading were called slut's pennies, 18c.). Meaning "woman of loose character, bold hussy" is attested from mid-15c.; playful use of the word, without implication of loose morals, is attested from 1660s.

Our little girl Susan is a most admirable slut, and pleases us mightily. [Pepys, diary, Feb. 21, 1664]

Sometimes used 19c. as a euphemism for bitch to describe a female dog. There is a group of North Sea Germanic words in sl- that mean "sloppy," and also "slovenly woman," and that tend to evolve toward "woman of loose morals" (cf. slattern, also English dial. slummock "a dirty, untidy, or slovenly person," 1861; M.Du. slore "a sluttish woman").

What provoked rh to talk about the bitch/slut connection was Richard Lawrence Cohen saying:

Is Fluke going to sue, or is she suing, this son of a bitch for defamation? I would think it's defamation per se.

Which prompted me to say:

Is Limbaugh's mother going to sue you for calling her a dog? She's clearly not a dog.