M. Heinonen et al., Detectability and prevalence of Brachyspira species in herds rearing health class feeder pigs in Finland, VET REC, 146(12), 2000, pp. 343-347
Faeces samples were taken three times at two-week intervals, from the farro
wing units of four herds of known Brachyspira (formerly Serpulina) status a
nd one of unknown Brachyspira status. Brachyspira hyodysenteriae, Brachyspi
ra pilosicoli, Brachyspira intermedia and Brachyspira group iii were isolat
ed from the faecal samples from the weaners in the herds using either a max
imum of 50 ppm of olaquindox or no feed additives. The detection rates were
relatively consistent. However, B hyodysenteriae was not detected at one s
ampling in a known positive herd. The prevalence of Brachyspira species was
also studied in feeder pigs originating from LSO 2000 health class farrowi
ng units, comparable with specific pathogen-free herds. These farms were fr
ee from swine dysentery, sarcoptic mange, swine enzootic pneumonia and prog
ressive atrophic rhinitis. Fifty of 428 herds were sampled once. B hyodysen
teriae was not isolated from any of them, but B intermedia, B pilosicoli an
d Brachyspira group III were isolated from five, 14 and 37 of the herds, re
spectively. The detection of Brachyspira species did not relate to the prev
alence of diarrhoea in the herds, as judged by the farmers. The herds using
carbadox (40 to 50 ppm) had a lower prevalence of Brachyspira species than
those using olaquindox (40 to 50 ppm).