Distribution of Brachyspira hyodysenteriae and Lawsonia intracellularis in healthy and diarrhoeic pigs

Although Brachyspira (B.) hyodysenteriae and Lawsonia (L.) introcellularis are widely distributed in pigs in Germany, there exists limited information on their clinical relevance. To get more insight into their potential role in swine diarrhoeal disease, in 2002 and 2003 faecal specimens from healthy pigs (n= 1445) as well as from diarrhoeic pigs (n=2002) were tested by polymerase chain reaction (PCR) for the presence of both agents. Of the specimens from healthy pigs L.intracelluloris and B.hyodysenteriae were detected in 7.3% and 6.7%, respectively. In contrast, of the diarrhoeic pigs the ratios of positive samples amounted to 19.4% for L.intracelluloris and 17.9% for B.hyodysenteriae. Concerning the age of the diseased animals, in growing pigs the detection rates of L.intracellularis and B.hyodysenteriae were nearly identical (16.4% and 14.2%, respectively). In fattening pigs a significant higher number of animals were affected with B.hyodysenteriae (35.8%) than with L. intracellularis (28.2%). On the other hand, in sows L.intracellularis (35.6% positive samples) was dominant compared to B.hyodysenteriae (21,2 positive samples). Considering the nearly threefold higher percentage rates of L.intracellularis and B.hyodysenteriae in diarrhoeic pigs in comparison to healthy pigs, it is concluded that both agents play an important role in swine diarrhoeal disease. The results further indicated that in fattening pigs B.hyodysenteriae and in sows L.intracellularis have a dominant role, respectively.