Sheepdog breed (6)
I believe the answer is:
collie
'sheepdog breed' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for collie that I've seen before include "Scottish sheepdog" , "Farm dog" , "Long-haired intelligent dog" , "Silky-coated sheepdog" , "Type of sheepdog" .)