1. Felv is a viral disease that can affect cats of all ages.
猫白血病是一种可以影响各个年龄段的猫的病毒性疾病。

2. Cats infected with Felv may experience various symptoms such as anemia and immune system suppression.
感染猫白血病病毒的猫可能会出现贫血和免疫系统抑制等各种症状。