The habit a disappointed dog owner had got into? (6,7)
I believe the answer is:
mother hubbard
'the habit' is the definition.
(Mother Hubbard is a type of garment or habit)
I can't explain the remainder of the clue.
(Other definitions for mother hubbard that I've seen before include "She tried unsuccessfully to give her dog a bone" , "She was out of bones!" , "Long, loose dress" , "Her dog went boneless" , "went into empty cupboard" .)