Provided are methods of treating feline Coronavirus infections comprising administering a therapeutically effective amount of a compound of Compound 1 to Compound 9, or a pharmaceutically acceptable salt thereof.本發明提供治療貓冠狀病毒感染之方法,其包含投與治療有效量之化合物1至化合物9之化合物或其醫藥上可接受之鹽。