It is non-enveloped, double-stranded RNA virus. The genome is segmented. Circoviruses Circoviruses are small single-stranded DNA viruses. There are two genera: gyrovirus, with one species called chicken anemia virus; and circovirus, which includes porcine circovirus types 1 and 2, psittacine beak and feather disease virus, pigeon circovirus, canary circovirus, goose circovirus. Herpesviruses Herpesviruses are ubiquitous pathogens infecting a variety of animals, including humans. Hosts include many economically important species such as abalone, oysters, salmon, poultry (avian infectious laryngotracheitis, Marek's disease), cattle (bovine malignant catarrhal fever), dogs, goats, horses, cats (feline viral rhinotracheitis), and pigs (pseudorabies). Infections may be severe and may result in fatalities or reduced productivity. Therefore, outbreaks of herpesviruses in livestock cause significant financial losses and are an important area of study in veterinary virology. African swine fever virus African swine fever virus (ASFV) is a large double-stranded DNA virus which replicates in the cytoplasm of infected cells and is the only member of the Asfarviridae family. The virus causes a lethal haemorraghic disease in domestic pigs. Some strains can cause death of animals within as little as a week after infection. In other species, the virus causes no obvious disease. ASFV is endemic to sub-Saharan Africa and exists in the wild through a cycle of infection between ticks and wild pigs, bushpigs and warthogs. Retroviruses Retroviruses are established pathogens of veterinary importance. They are generally a cause of cancer or immune deficiency. Flaviviruses Flaviviruses constitute a family of linear, single-stranded RNA(+) viruses. Flaviviruses include the West Nile virus, dengue virus, Tick-borne Encephalitis Virus, Yellow Fever Virus, and several other viruses. Many flavivirus species can replicate in both mammalian and insect cells. Most flaviviruses are arthropod borne and multiply in both vertebrates and arthropods. The viruses in this family that are of veterinary importance include Japanese encephalitis virus, St. Louis encephalitis virus, West Nile virus, Israel turkey meningoencephalomyelitis virus, Sitiawan virus, Wesselsbron virus, yellow fever virus and the tick-borne flaviviruses e.g. louping ill virus. Paramyxoviruses Paramyxoviruses are a diverse family of non-segmented negative strand RNA viruses that include many highly pathogenic viruses affecting humans, animals, and birds. These include canine distemper virus (dogs), phocine distemper virus (seals), cetacean morbillivirus (dolphins and porpoises) Newcastle disease virus (birds) and rinderpest virus (cattle). Some paramyxoviruses such as the henipaviruses are zoonotic pathogens, occurring primarily in an animal hosts, but also able to infect humans. Parvovirus Parvoviruses are linear, non-segmented single-stranded DNA