Symptoms of cats suffering from peritonitis: 1. They will lose energy at first, eat less and be accompanied by fever; 2. Due to abdominal inflammation, in the middle stage, they will have arched back, pain when standing, and difficulty breathing; 3. In severe cases, the abdomen will be swollen and accumulated. A large amount of ascites can cause the cat's internal organs to decline. In addition, cat peritonitis is divided into two types: wet type and dry type. The most obvious symptoms of dry type are the eyes and internal organs, and the main symptom of wet type is internal ascites.