Shoo the cat away — no small trouble for canine? (9)
I believe the answer is:
toothache
'shoo the cat away no' is the definition.
I can't tell whether this defines the answer.
'small trouble for canine?' is the wordplay.
'small trouble' becomes 'ache' (I am not sure about this - if you are sure you should believe this answer much more).
'for' means one lot of letters go next to another (I've seen this in other clues).
'canine?' becomes 'tooth' (canine is a kind of tooth).
'ache' put after 'tooth' is 'TOOTHACHE'.
Can you help me to learn more?
(Other definitions for toothache that I've seen before include "Oral discomfort" , "Odontalgia" , "It causes grief" , "Dental pain" , "Trouble with choppers" .)