Concurred with dog (3)
'dog' is the definition.
(cur is a kind of dog)
'concurred with' is the wordplay.
'with' says the answer is hidden in the clue.
'CUR' is hidden in the letters of 'concurred'.
(Other definitions for cur that I've seen before include "Base fellow", "Mongrel - coward", "Poor dog", "Vile dog", "Mongrel - cowardly person".)