Dog in the street going mad (6)
I believe the answer is:
setter
'dog' is the definition.
(setter is a type of dog)
'street going mad' is the wordplay.
'going mad' indicates an anagram.
'street' is an anagram of 'SETTER'.
'in the' is the link.
(Other definitions for setter that I've seen before include "Hunting dog" , "Mike of this parish, say" , "Silky-coated gun dog" , "A dog trained to stand still when it scents game" , "Crossword composer" .)