Doctor asks Fred to bag mess (4,9)
I believe the answer is:
dogs breakfast
'mess' is the definition.
(I've seen this before)
'doctor asks fred to bag' is the wordplay.
'doctor' indicates an anagram.
'asks'+'fred'+'to'+'bag'='asksfredtobag'
'asksfredtobag' anagrammed gives 'DOGS BREAKFAST'.
(Other definitions for dogs breakfast that I've seen before include "Mess (food for Fido?)" , "Darkest of bags (anag)" , "Mess, shambles" , "A horrible mess" , "Untidy mess (to feed pet?)" .)