DIAGNOSING SALMONELLOSIS IN HORSES - CULTURING OF MULTIPLE VERSUS SINGLE FECAL SAMPLES

Three rectal faecal samples were taken at 24-hour intervals from 136 h orses in order to investigate whether multiple faecal cultures yield a greater number of Salmonella-positive horses compared to single faeca l cultures. Of these 136 horses, 89 were suspected of salmonellosis on clinical grounds and 47 belonged to a control group. From the 'Salmon ella suspected' group, 22 horses (25 %) were Salmonella positive on on e or more occasions. Only twelve of these 22 positive horses (55 %) we re positive at first sampling. Of the control group, only three horses (6 %) were positive for Salmonella. Thirty-one (69 %) of the 45 posit ive cultures from the 'Salmonella suspected' group were found only aft er enrichment in Selenite broth. From the results of the present study it is concluded that multiple faecal cultures are superior to single faecal cultures for diagnosing clinical salmonellosis in horses and th at there is no relation between the course of the disease and whether the Salmonellae were cultured directly or indirectly, after enrichment in Selenite broth. Salmonellae were cultured from the faeces of horse s treated with antibiotics before their referral, even when the isolat ed strain was sensitive to the antimicrobial drug used by the practiti oner.