Pooch (3)
'pooch' is the definition.
(pooch can informally mean a dog)
This is all the clue.
(Other definitions for dog that I've seen before include "St Bernard, for example" , "'Every ... is allowed one bite'" , "Follow closely; animal" , "boxer?" , "Lassie" .)
(Other definitions for mutt that I've seen before include "Mongrel dog - foolish person" , "Mongrel - fool" , "Chump" , "Setter perhaps" , "Dog of mixed breed" .)
'pooch' is the definition.
(I know that pooch can be written as doggie)
This is the entire clue.
(Another definition for doggie that I've seen is " pet".)
(Other definitions for doggo that I've seen before include "(Lie) silent and in hiding" , "keeping mum out of the picture?" , "hidden away" , "(Lie) in concealment" , "in secret" .)