My cat is an outdoor cat and is frequently outside for varied amounts of time. I had just fed him and let him out the door. When I returned to check if he was on the porch, he came out of his hiding spot with a small injury at his mouth and his right eyelid seemed to be swollen and red. He is momentarily hiding under furniture, and when he entered he went straight to his favorite spot, almost in shock or panic. What should I do?