The symptoms are not very obvious at first, and the owner needs to observe carefully: if there are fever, loss of appetite, lack of energy, weight loss, difficulty breathing and other similar conditions, it is difficult to rule out that it is not peritonitis. In the later stages, when the disease is severe, the cat will have obvious symptoms of abdominal swelling, red eyes with inflammation, and twitching and panting. Among them, cats or kittens with low immunity are prone to feline-transmitted abdominal disease and peritonitis.