Dog walker under the influence of alcohol? (7)
I believe the answer is:
lurcher
'dog' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
(Other definitions for lurcher that I've seen before include "Greyhound-collie cross" , "Crossbred hunter" , "inclined to leave people in difficulties?" , "a hunting animal" , "A greyhound cross" .)