Canine in Oz (4)
I believe the answer is:
toto
'canine in oz' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for toto that I've seen before include "[FRIEND OF DOROTHY]" , "Dorothy's dog in The Wizard of Oz" , "member of the 5d band" , "Famous film dog" .)