A bird dog by name (6)
I believe the answer is:
curlew
'a bird' is the definition.
(curlew is a kind of bird)
'dog by name' is the wordplay.
'dog' becomes 'cur' (a cur is an aggressive or scruffy dog).
'by' says to put letters next to each other.
'name' becomes 'lew' (I can't justify this - if you can you should give a lot more credence to this answer).
'cur'+'lew'='CURLEW'
Can you help me to learn more?
(Other definitions for curlew that I've seen before include "Wading bird with long down-curved beak" , "Flyer" , "Curve-beaked bird" , "Shorebird of the sandpiper family" , "Large wader of the sandpiper family" .)