Submitted to: Animal Reproduction Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2000
Publication Date: N/A
Interpretive Summary: From a global perspective, porcine parvovirus and porcine reproductive and respiratory syndrome virus are the most common causes of virus-induced porcine reproductive failure. It is estimated that their collective cost to the swine industry in North America alone is at least several hundred million dollars annually. In this manuscript we focus on information, gleaned in part from our current studies, that is useful in understanding, diagnosing, preventing, and controlling these 2 diseases. This information can be used to appreciably reduce their prevalence, and consequently their economic impact on commercial swine production.
Technical Abstract: From a worldwide perspective porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) are the most common viral causes of porcine reproductive failure. A typical epidemic of PPV-induced reproductive failure is presented as an increased number of mummified fetuses and sometimes entire litters are mummified. If infection with PPV is very early in gestation the number of liveborn pigs may be further reduced as a result of embryonic death and resorption. During the acute stage of infection gilts and sows have few if any clinical signs, and it is unlikely that PPV is ever the direct cause of abortion. In contrast, a typical epidemic of PRRSV-induced reproductive failure is presented as a broader spectrum of clinical features including abortions, late-term dead fetuses, stillborn pigs, and weakborn pigs. In the later stages of an epidemic there may also be an increase in the number of mummified fetuses, but their prevalence is likely to be far less than during an epidemic of PPV-induced reproductive failure. During the acute stage of infection with PRRSV gilts and sows may have few if any clinical signs, or they may be severely affected and even die. This difference largely reflects the relative virulence of the strain of PRRSV causing the epidemic. A timely and reliable laboratory diagnosis of either disease can be made when appropriate tests are performed with appropriate samples. Vaccines are available for prevention of both diseases.