THE PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME PANZOOTIC

Porcine reproductive and respiratory syndrome (PRRS) has affected pigs in most major pig-producing countries of the world, In North America. clinical signs began as early as 1987 and had spread across Europe by 1992. Many countries, aware of the Economic loss that results from PR RS, instituted government programs to identify and eradicate PRRS as i t entered their countries. Despite governmental efforts, PRRS continue d to spread. The PRRS virus is most likely spread to naive herds throu gh carrier breeding stack animals or artificial insemination. Currentl y, there are tests to evaluate semen before it is used, Naive herds br eaking with PRRS have increased numbers of mummified and stillborn pig s and high preweaning mortality. Chronic PRRS causes respiratory probl ems and increased mortality in nursery and grower pigs To prevent the problems PRRS causes, producers ''blitz''-vaccinated their sows by vac cinating most or all of them at one time. Current use of the PRRS vacc ine is limited to a specific stage of gestation or to open sows.