You once also bitten by the barking canine (3,5)
I believe the answer is:
eye tooth
'canine' is the definition.
(I've seen this before)
'you once also bitten by the barking' is the wordplay.
'you once' becomes 'ye' (archaic version of 'you').
'also' becomes 'too' (synonyms).
'bitten by' means one lot of letters goes inside another (I've seen this in other clues).
'barking' is an anagram indicator (UK slang for mad).
'ye'+'too'='yetoo'
'the' anagrammed gives 'eth'.
'yetoo' placed into 'eth' is 'EYE-TOOTH'.
(Another definition for eye tooth that I've seen is " Canine".)