Train every working animal doctor (10)
I believe the answer is:
veterinary
'animal doctor' is the definition.
(I've seen this before)
'train every working' is the wordplay.
'working' indicates anagramming the letters.
'train'+'every'='trainevery'
'trainevery' with letters rearranged gives 'VETERINARY'.
(Other definitions for veterinary that I've seen before include "Animal doctor" , "Like some surgeons" .)