This disease is a common disease of arhat, but it is usually not easy to treat. Sometimes even if it is cured, this arhat will be abolished (visceral failure, body will not grow very big, appetite is not strong, and color is not bright). ) This disease, commonly known as bulging eye disease, is caused by multiple infections of bacteria and parasites. There are many complications of this disease, usually accompanied by blindfolding, loss of appetite, internal organ failure and so on. So my suggestion is to give up treatment. If you are unwilling to give up, try formaldehyde. Formaldehyde is highly toxic, but it can kill this kind of bacteria, and the amount must be small, because it will endanger the life of your favorite fish. Generally, 0.5ml is put in fish tanks No.3, No.6 and No.9, and the water is changed to 1/2 after 2 hours, and the medicine is continued for 12 hours. Generally, three times is a course of treatment, then the whole tank is changed with water, and the second course of treatment is carried out after 3 days until it is good. Stop feeding during drug release, keep enough oxygen, clear water and keep the temperature at 28 degrees.