A dog from Naples I trained (7)
I believe the answer is:
spaniel
'a dog' is the definition.
(spaniel is a kind of dog)
'naples i trained' is the wordplay.
'trained' is an anagram indicator (to train can mean to grow something into a shape).
'naples'+'i'='naplesi'
'naplesi' anagrammed gives 'SPANIEL'.
'from' acts as a link.
(Other definitions for spaniel that I've seen before include "Droopy-ear dog" , "Breed of dog" , "Dog with long silky coat" , "Type of dog" , "Droopy-eared dog" .)