Author : William T. Christianson
Publisher :
ISBN 13 :
Total Pages : 414 pages
Book Rating : 4.:/5 (319 download)
Book Synopsis Clinical, Etiologic, and Pathogenic Investigation of an Emergent Procine Reproductive Disease by : William T. Christianson
Download or read book Clinical, Etiologic, and Pathogenic Investigation of an Emergent Procine Reproductive Disease written by William T. Christianson and published by . This book was released on 1993 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Porcine reproductive and respiratory syndrome (PRRS) has emerged in the last several years as an important viral disease of swine. The disease has been reported in all major swine producing regions of North America and Europe. The goal of this thesis was to describe clinically the syndrome in herds, to define the etiologic agent responsible for the reproductive failure and to investigate the pathogenesis of the reproductive failure. In Chapet 1, the PRRS literature is reviewed Chapter 2 is a report of clinical investigations of two PRRS outbreaks. Reproductive and neonatal losses are documented and the opportunity costs associated with the syndrome on the farms are calculated. Transplacental infection with encephalomvocarditis virus (EMCV), an early proposed etiologic agent is investigated in Chapter 3. Transplacental infections with EMCV was archieved but the agent was ruled out as the cause of PRRS. The purpose of the study reported in Chapter 4 was to experimentally reproduce PRRS in late-term pregnant sows. Lung homogenates containing the newly discovered PRRS virus, and cell culture propagated virus, were used to demonstrate that PRRS virus was the causative agent of PRRS reproductive failure. A basic understanding of the pathogenesis of PRRS virus in late-gestation sows is described in Chapter 4. Chapter 5 describes studies on the pathogenesis of PRRS virus in mid-gestation sows and their fetuses. The results of Chapter 5 indicate mid-gestation sows and fetuses are susceotible to PRRS virus, but the virus does not readily cross the placenta during mid-gestation. From these studies a greater understanding of an important new swine viral disease emerges - a clinical description of PRRS is attained, the etiologic agent of PRRS is defined and an understanding of the pathogenesis of PRRS virus in pregnant sows is achieved.
