I can’t answer that for you. Are you peeing more or noticing blood in your urine? Don’t answer that; I’m not the person you need to be talking to about those symptoms.

Kidney disease is very common in cats. According to this that number is 80% of cats over the age of 15. So I apologize if I sounded alarmist; there are other reasons a cat might refuse food, but something to consider for the sake of your fur babies.