Herding dog (6,6)
(Other definitions for border collie that I've seen before include "Working sheepdog" , "Type of sheepdog" , "Dog commonly used for herding sheep" , "Sheepdog breed" .)
'herding dog' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for collie that I've seen before include "Scottish sheep dog" , "Sheepdog with long pointed muzzle" , "See 2" , "Long-haired intelligent dog" , "Shepherd's dog" .)