Experimental swine dysentery: comparison between infection models

The aim of the present study was to develop a reproducible porcine infection model with Brachyspira hyodysenteriae. The influence of different factors was evaluated, namely, age, a diet containing large quantities of soybean meal, housing and administration of cortisol or antacids. Furthermore, the synergistic effect of additional bacteria (Escherichia coli O141, Bacteroides vulgatus ora mixture of Bacteroides fragilis, a field isolate of Bacteroides and Fusobacterium, necrophorum) was studied. Experimental infection resulted in an increase in the serum concentrations of the acute-phase proteins serum amyloid A and haptoglobin and the percentages of neutrophils and monocytes. These alterations were specifically related to haemorrhagic diarrhoea. Inoculation combined with feeding of large quantities of soybean meal and group-housing induced swine dysentery in all experimental animals. If the pigs were fed soybean meal, kept in single pens and circulated between the pens, five out of nine developed disease.