Canine pest (4)
I believe the answer is:
flea
'canine pest' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for flea that I've seen before include "Member of a circus?" , "Small blood-sucking insect" , "Jumping, biting insect" , "high-jumper" , "little pest" .)