Russian wolfhound (6)
I believe the answer is:
borzoi
'russian wolfhound' is the definition.
(borzoi is a breed of dog)
This is all the clue.
(Other definitions for borzoi that I've seen before include "Russian hound" , "Russian dog bred for hunting wolves" , "Russian wolfhound" , "Dog like a huge greyhound" , "Zoo rib (anag)" .)