Porcine circovirus 3 (PCV3) is a single-stranded DNA virus that is non-enveloped with an unsegmented circular genome about 2 kb in length. PCV3 belongs to the family Circoviridae and represents the third member of the genus Circovirus of which there are four known variants. PCV3 was first isolated in 2015 from a sow farm experiencing increased mortality and decreased conception rate. Studies have since demonstrated that PCV3 was present in pigs by early 1990s and is currently widespread worldwide. However, clinical symptoms associated with PCV3 infection are not well understood. Evidence suggests that PCV3 infection may lead to reproductive problems, but viral DNA has been found in healthy pigs, as well as animals displaying various other clinical symptoms.