Morbillivirus is a genus of viruses in the order Mononegavirales, in the family Paramyxoviridae, in the subfamily Paramyxovirinae. Humans, dogs, cats, cattle, and cetaceans serve as natural hosts. There are currently six species in this genus, including the type species Measles virus. Diseases associated with this genus include: measles: fever, rash; animal: acute febrile respiratory tract infection.