Animal doc (3)
I believe the answer is:
vet
'animal doc' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for vet that I've seen before include "Critically examine" , "Examine carefully - might one help a lame duck?" , "Examine carefully for suitability" , "A diminutive animal doctor" , "Experienced" .)