Little doggies carrying master's shoes (5)
I believe the answer is:
pumps
'shoes' is the definition.
(pump is a kind of shoe)
'little doggies carrying master's' is the wordplay.
'little doggies' becomes 'pups' (puppies).
'carrying' means one lot of letters goes inside another.
'master' becomes 'm'.
'pups' placed around 'm' is 'PUMPS'.
(Other definitions for pumps that I've seen before include "Moves fluid or gas by pressure or suction" , "Cycle attachments" , "footwear" , "leading questions" , "Mechanical devices that move fluid or gas" .)