猫的冠状病毒变异，准确地说，冠状病毒DNA的3C或（和）7B位点上出现缺失，猫会罹患FIP。FIP从免疫学的角度看像一种肿瘤性疾病。没治。

但，猫的冠状病毒（FCoV）对不是传染性腹膜炎病毒（FIPV）。这点要厘清。有些兽医采用FCoV的抗原检测试纸测试疑似的病例以此诊断FIP，缺乏科学依据，几近笑谈。

猫的冠状病毒通常在群居的猫中发病。所谓群居，实际上是群养。例如猫舍、救助站、爱心人士的救助场所、动物医院等，猫的冠状病毒通过粪便传播。应急状态（或者免疫力低下）包括改变环境、拥挤、免疫、育、嘈杂等会诱导FCoV变异为FIPV。这是我反复告诫流浪猫的救助者无需按照人的生活方式群养猫咪的依据之一。而事实上，大多数流浪猫的救助者都遇到了传染的FIP的情况，往往还真认定FIP就是传染病。

猫的冠状病毒往往只引起猫轻度的胃肠炎症状，大多通过对症治疗就能控制。所以某种程度上，猫的冠状病毒无需过度诊断和治疗。但一旦出现特定的变异，治疗也无临床意义了。

Coronavirus mutation in cats. Specifically, if there are deletions at 3C or (and) 7B of coronavirus DNA, cats will develop FIP. From an immunological point of view, FIP is a neoplastic disease. Hopeless.

However, the cat coronavirus (FCoV) is definitely not infectious peritonitis virus (FIPV). Let's make that clear. Some veterinarians use FCoV antigen test strips to test suspected cases to diagnose FIP, which lacks scientific evidence and is close to a joke.

Cat coronavirus usually develops in cats that live in groups. What is called group living is actually group breeding. For example, cat houses, rescue stations, rescue places for caring people, animal hospitals, etc., the coronavirus of cats is transmitted through feces. Emergency conditions (or immunodeficiency), including changes in the environment, crowding, immunity, sterilization, noise, etc., induce FCoV to mutate into FIPV. This is one of the reasons I have repeatedly told stray cat rescuers not to herd cats according to human lifestyles. In fact, most stray cat rescuers have been exposed to infected FIP, which is often considered an infectious disease.

Coronavirus in cats often causes only mild gastroenteritis in cats, which can be controlled with symptomatic treatment. So in a way, coronaviruses in cats don't need to be overdiagnosed and overtreated. But once a particular mutation is present, the treatment makes no clinical sense.