Sick swine in a pig farm have been studied in epidemiology, clinicopathology, etiology and serology. The results shows that the disease occurs in pregnant sows and postweaning piglings. Its symptoms on sows are abortion, dead fetus and mummified fetes and that on the pigling are dyspenic respiration, cyanosis, labar pneumonia, hemorrhagic lymphnoditis and hematosepsis, Testing by ELISA and RT-PCR, it is positive in Porcine Reproductive and Respiratory Syndrome (PRRS). In the macrophagocyte of the lung, pul...