An outbreak of diarrhoea in hoggets associated with infection by Yersinia enterocolitica.

An outbreak of diarrhoea in a flock of 450 Romney hoggets was investigated. The flock was receiving suboptimal pasture allowance on an intensive 4-day controlled grazing rotation. Approximately 30% were affected with a foul-smelling diarrhoea and four died. Yersinia enterocolitica was isolated from small and large intestines of three affected sheep. Organisms consistent in appearance with Yersinia spp. were demonstrated in suppurative foci in the lamina propria of the small and large intestines. Affected animals were removed from the mob and appeared to respond clinically to tetracycline therapy. The outbreak lasted about two weeks.