Seroprevalence of Lawsonia intracellularis Infection in Swine Breeding Herds in Thailand

Introduction Proliferative enteropathy in pigs is manifested as bloody diarrhea/sudden death in adults and chronic diarrhea/slow growth in younger pigs (1). The disease is caused by infection with Lawsonia intracellularis (LI), an obligate intracellular organism. The economic impact of this disease is most severe in grower and finisher pigs. In the field, the earliest reports of natural LI fecal shedding were in piglets 3 weeks old (2). Therefore, it is possible that the infection initially occurred during the lactation period in which the sow may be a source of horizontal transmission. Therefore, it is important to know the infectious status of LI in breeding herds. To date, little information is available on the infection dynamic of LI in breeding herds in Thailand. The objective of this study was to determine the prevalence of LI infection in sows and gilts in breeding herds in Thailand using an immunoperoxidase monolayer assay (IPMA).