Little child is to clean dog perhaps (6)
I believe the answer is:
moppet
'little child' is the definition.
(moppet can informally mean a child)
'clean dog perhaps' is the wordplay.
'clean' becomes 'mop' (mopping is a kind of cleaning).
'dog perhaps' becomes 'pet' (dogs are often kept as pets).
'mop'+'pet'='MOPPET'
'is to' acts as a link.
(Other definitions for moppet that I've seen before include "Little darling" , "Little girl" , "young child" , "Tot" , "Little child" .)