My Bonaparte started sneezing last weekend, and then went off his food. I got him to the vet on Tuesday and he had a fever. She put him on doxycycline antibiotics and Tolfadine to bring his temperature down. I have put him in a room on his own in case there is something infectious. Yesterday he seemed better and ate and drank a little, even did a pee. But today he has not been so good, and is very lethargic, just wanting to sleep. He has eaten and drunk a little, but no pee or poop today, and his temperature is up again to 40.7. I am taking him back to the vet tomorrow. Since his urinary surgery four years ago he has been a very healthy, if overweight, cat, so I am very concerned. The fact that he is sneezing makes me think it is nothing to do with his urinary system, but why is he not peeing at least? I think tomorrow that maybe blood test and ultrasound may be necessary.