PRRSV – Porcine Reproductive and Respiratory Syndrome Virus
The disease caused by this virus is called Porcine Reproductive and Respiratory Syndrome (PRRS) and, as indicated by its name, is causing reproductive disease in sows and respiratory disease in swine. Infected farms may experience problems in sows, growing pigs or both. A variety of factors, including swine genetics, PRRSV strain, health status of the herd, age of the affected animals and stage of pregnancy may influence the clinical signs. In naïve breeding herds, PRRSV infection may cause anorexia, fever and abortions. In addition, an endemic course of the disease may cause an increase in the number of mummies, stillborn and weak-born piglets, and an increased rate of returns to estrus. Sows often show no further clinical signs, however, infection with more virulent strains can lead to discoloration of the skin (e.g. ears and snout), fever and may cause death of sows. Respiratory symptoms, predominantly labored breathing, are mainly seen in growing pigs. Those may go along with anorexia, lethargy, fever, conjunctivitis, eyelid edema as well as discoloration of the skin (e.g. ears and snout). PRRSV infection of the lung does lead to a higher risk of secondary infections. Within the herd disease may cause an increase of losses and uneven growth. PRRSV is transmitted by direct contact of pigs, semen, aerosols, insects and other fomites as well as medical procedures (needle management!).
No targeted therapy is available for PRRS. Prophylactic vaccination is the preferred measure to control virus replication and clinical symptoms within infected herds. However, for successful PRRS control also biosecurity should be checked and improved as necessary. The key is to: prevent infection, maximize immunity and minimize exposure. A systematic approach (5 Step-Process) helps to integrate all aspects.
