Hi Joyce,
I know it's agonizing to see one of your furbabies sick. As long as he is still eating and drinking, though, it's probably ok to wait until your vet opens on Tuesday, but if he goes more than 12 to 18 hours without doing either, you should probably take him in. And if he DOES stop eating, you should probably check his temperature. :shock: (Hint: you can't take it in his mouth, and you should label that thermometer "CAT" from now on"). If his temp is more than 102 (101 to 102 is normal for cats) then he needs to be seen immediately.
The eating and drinking a lot could mean he has developed diabetes, and is having the excess urine production that diabetes causes. Is he overweight? Or been losing weight lately?
Plus, for all of you who have had pet "accidents", there is only one product I've ever found that actually removes ALL odors and stains and that is Oreck's Enzyme Odor Remover. It gets it out completely. Can't recommend it enough. Get it from your local Oreck dealer, or order it online.
Good luck with your baby.
Gai