Faint smell around pet's penetrating (4,4)

I believe the answer is:

keel over

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'faint' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for keel over that I've seen before include "Pass out" , "Fall, as in a faint" , "Suddenly collapse" , "Capsize" .)

I've seen this clue in The Guardian.

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