Right in the middle of tooth, one kind of canine (5)
I believe the answer is:
corgi
'kind of canine' is the definition.
(I know that corgi is a type of dog)
'right in the middle of tooth one' is the wordplay.
'right' becomes 'r' (abbreviation).
'in the middle of' indicates putting letters inside.
'tooth' becomes 'cog' (cog is a kind of tooth).
'one' becomes 'i' (Roman numeral).
'r' placed within 'cog' is 'corg'.
'corg'+'i'='CORGI'
(Other definitions for corgi that I've seen before include "pet in 9 [CARDIFF]?" , "Welsh 11" , "found in the kennels" , "Cardigan or Pembroke dog" , "Dog popular with British royals" .)