Gunner was so reliable that the commanding officer of 2 Squadron, Wing Commander A. B. "Tich" McFarlane, gave approval for Westcott to sound a portable air raid siren whenever Gunner's whining or jumping alerted him.[6] Later, when a number of stray dogs were roaming the base and becoming a nuisance, McFarlane ordered that all dogs other than Gunner were to be shot.[7]