A retrovirus that primarily affects cats, is transmitted through saliva, and causes suppression of the immune system and anemia, leading to opportunistic infections and diseases such as leukemia and lymphoma.滤过性猫科白血病毒：主要感染猫类的逆转滤过性病毒（一种致癌病毒），经由唾液传染并会引起免疫系统及贫血症受到抑制，导致遭受感染的可能性及传染性疾病例如白血病及淋巴瘤等