The Collaborative International Dictionary of English v.0.48:

Bandog \Ban"dog`\ (b[a^]n"d[o^]g`; 115), n. [Band + dog, i.e.,
   bound dog.]
   A mastiff or other large and fierce dog, usually kept chained
   or tied up.
   [1913 Webster]

         The keeper entered leading his bandog, a large
         bloodhound, tied in a leam, or band, from which he
         takes his name.                          --Sir W.
                                                  Scott.
   [1913 Webster] Bandoleer

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "bandog":
   Cerberus, Seeing Eye dog, bitch, bowwow, canine, dog, fancy dog,
   guard dog, guide dog, gyp, kennel, lap dog, pack of dogs, pooch,
   pup, puppy, sheep dog, show dog, sled dog, slut, toy dog, watchdog,
   whelp, working dog