Dog given remedial treatment by Ed (3)
I believe the answer is:
cur
'dog' is the definition.
(both can mean a despicable person)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for cur that I've seen before include "Lowly dog" , "Base fellow" , "Mongrel - coward" , "Inferior dog or one of mixed breed" , "Mangy dog" .)