A little dog - perhaps one plays with it (3,7)
I believe the answer is:
Here is my best explanation:
'a little dog' is the definition.
'perhaps one plays with it' is the wordplay.
'perhaps' is an anagram indicator.
'with' means one lot of letters go next to another.
'oneplays' put after 'it' is 'itoneplays'.
'itoneplays' anagrammed gives 'TOY SPANIEL'.
(Another definition for toy spaniel that I've seen is "small dog".)