Doc for pets (3)
I believe the answer is:
vet
'doc for pets' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for vet that I've seen before include "'Animal doctor, in short (3)'" , "Ex-serviceman" , "solider once" , "Examine, check" , "Examine carefully - might one help a lame duck?" .)