It is very likely to be feline plague, but if you want to confirm the diagnosis, you still need to go to a nearby pet hospital for examination. Generally speaking, cats will have other symptoms when their fever reaches 40 degrees. If the cat vomits, has diarrhea and blood, and has a high fever If it does not subside, it can be determined to be feline plague. It is recommended that the owner send the cat to the pet hospital for treatment in time. If the cat only has a high fever and has no other symptoms, it may be a high fever caused by a cold. The owner only needs to reduce the cat's fever.