Sales pitch about a new breed of dog (7)
I believe the answer is:
spaniel
'breed of dog' is the definition.
(I've seen this before)
'sales pitch about a new' is the wordplay.
'sales pitch' becomes 'spiel' (I've seen this before).
'about' means one lot of letters goes inside another.
'a new' becomes 'an' (I've seen this in other clues).
'spiel' placed around 'an' is 'SPANIEL'.
(Other definitions for spaniel that I've seen before include "Dog found among the alpines" , "[HOUND]" , "Breed of dog" , "Dog - leaps in (anag)" , "Alpines (anag)" .)