Beech 1900-C pilot reported the Number 2 engine inboard nacelle panel departed the aircraft and struck the tail during a go-around.

Narrative

Pilot heard a loud metallic scraping noise during a go-around (due to animal(s) on runway). Immediate use of trim was necessary to restabilize the climbout instructions at a level attitude. It was discovered immediately after landing that the inboard nacelle panel on number 2 engine departed the aircraft and struck the tail. The safety of the pilot and aircraft was never in question; and loss of directional control was never a concern. As previously stated; the noise in the air was my first clue; followed by visual confirmation on the ground after arrival. I am not a mechanic nor do I have much knowledge of the maintenance side of aviation; but if I had to wager a guess; I would say that the age and use of the panels in question have slowly deteriorated how 'flush' they are truly allowed to sit. I observed multiple cam-locks still in place; leading me to believe that the panel was ripped off; and not improperly secured. In-flight; mostly curiosity; but after establishing that the airplane and all the systems were performing normally; I simply resumed the go-around and the subsequent ILS back into ZZZ. However; afterwards; upon visual confirmation of something being out of the ordinary; the gravity of the situation set in. Fortunately; another company pilot was flying that evening and was a phenomenal immediate resource to me. Everyone has been extremely helpful; from the Chief Pilot; to all maintenance personnel involved. Again; my expertise isn't in the maintenance side of things; so any contribution I would have should be taken with a bucket of salt. I have begun banging on said panels as a preflight measure to ensure they're secure; but I'll reiterate that no part of me believes that the panel was improperly secured.