Long-haired sheepdog (6)
I believe the answer is:
collie
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">long-haired sheepdog</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for collie that I've seen before include "Farm dog" , "Type of sheepdog" , "Silky-coated sheepdog" , "Breed of dog" , "Sheepdog wth ling nose and shaggy hair" .)