call the vet place to hear thier advice (for next time?) - better than online(i dont always trust the internet lol). but i wouldnt know what to do, i prob would have done the same thing u did... i dont really know what a tick is, but there is a tick/flea meds maybe put that on him? i know a tick is a bug but i never had that experience.
i sugest you to call the vet office, and tell them your situation maybe it isnt anything cats can heal themselves pretty good, once my uncle when he was a teen (they told me the story about it) someone shot his cat with a BB gun, and the cat was "missing" for weeks, and she found a good hiding spot in the closet he didnt realize, and they didnt know she was shot, so the bb came out, and she healed herself.
cats do heal themselves pretty good, but i would call and see what they would think. that is a good idea i think i will call for "what ifs" cuz i dunno how they would get em if they were indoors.