Cat fever cannot be reduced by itself. When the cat is healthy, it will not show symptoms of fever. If you find that your cat has a high fever, you should first reduce the fever, and then check to see if there are any signs of cold or illness. If a cat has diarrhea and has no appetite, it may be that feline distemper virus exists in the body. It is recommended that the owner send the cat to a nearby pet hospital for examination and treatment.