Small, Alpine variety of dog (7)
I believe the answer is:
spaniel
'dog' is the definition.
(spaniel is a kind of dog)
'small alpine variety' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'variety' indicates anagramming the letters.
'alpine' is an anagram of 'paniel'.
's'+'paniel'='SPANIEL'
'of' acts as a link.
(Other definitions for spaniel that I've seen before include "Dog - leaps in (anag)" , "See 1 Across" , "Breed of dog" , "See 13" , "[HOUND]" .)