Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/5/1998
Publication Date: N/A
Technical Abstract: Porcine reproductive and respiratory syndrome (PRRS) is a viral disease of swine that was first recognized in the United States during the late 1980's as a few cases of reproductive failure in sows (abortions, stillborn pigs, weak pigs) and respiratory disease in young pigs. Since then this disease has been reported around the world and it is now one of the most significant diseases affecting the swine industry today. In 1996 severe cases of a PRRS-like disease were reported prompting investigations by several laboratories. These cases became known as Acute PRRS or Atypical PRRS based on the isolation of PRRS virus from some of these cases. This paper describes a study evaluating the effects of one of these PRRS virus isolates on pigs. The pigs experimentally infected with PRRS virus became severely affected just like pigs from field cases of Atypical PRRS. However, based on two diagnostic methods it appears that at least some of the pigs infected with PRRS virus and some of the non-infected control pigs were also infected with circovirus. The pigs are believed to have been infected with circovirus in utero prior to the beginning of the experiment. Additional studies are underway to evaluate the significance of this possible dual infection and any role it may have in Atypical PRRS.