Reduced having dog followed (9)
I believe the answer is:
curtailed
'reduced' is the definition.
(I've seen this before)
'dog followed' is the wordplay.
'dog' becomes 'cur' (a cur is an aggressive or scruffy dog).
'followed' becomes 'tailed' (I've seen this in another clue).
'cur'+'tailed'='CURTAILED'
'having' is the link.
(Other definitions for curtailed that I've seen before include "Reduced" , "docked" , "Clipped" , "Made short" , "limited" .)