One of my cats seems to have an eye infection. I'm taking him to the vet on Monday, but he normally stays outside. Sometimes he comes in for an hour or two at a time, but I'm going to try keeping him in until Monday (for two nights) because he might spread it to one of my other cats or it could get dirty, which might make it worse. Also, I can't be sure he'll show up on Monday. I have a cat bed and I'm setting up a litter box. He might want out soon, so what should I do?