Fecal shedding of Salmonella spp among cattle admitted to a veterinary medical teaching hospital

Abstract

OBJECTIVE- To estimate the prevalence of fecal shedding of Salmonella spp among bovine patients at a veterinary teaching hospital, to identify risk factors for fecal shedding of Salmonella organisms, and to characterize the serotypes. DESIGN- Retrospective cohort study. SAMPLE POPULATION- 5,398 hospitalized cattle. PROCEDURES- Data were collected for all cattle admitted during an 11-year period. Fecal shedding of Salmonella spp was determined by means of standard bacteriologic culture. Multivariable logistic regression models were used to identify risk factors for shedding of Salmonella spp among patients. RESULTS- The prevalence of Salmonella shedding among clinical suspects was 6.5% (50/768), whereas that among nonsuspects tested through routine surveillance was 2.5% (50/2,020). Among clinical suspect calves, fecal shedding of Salmonella spp was more likely for those admitted in the fall (odds ratio [OR], 5.9), those with septicemia (OR, 3.3), or those with an umbilical hernia (OR, 8.6). Among clinical suspect adult cattle, those with enteritis (OR, 9.9) or metritis (OR, 5.2) were more likely to be shedding Salmonella spp. Among nonsuspect cattle, none of the variables were significant predictors of shedding status. Twenty-one serotypes were detected during the study period, with the most common being Salmonella enterica serotypes Typhimurium (33%), Newport (23%), and Agona (12%). CONCLUSIONS AND CLINICAL RELEVANCE- Seasonal and disease risk factors for fecal shedding of Salmonella spp were evident among clinical suspect cattle admitted to a veterinary teaching hospital. In contrast, lack of significant associations among nonsuspect cattle would suggest that targeted screening within this population is not warranted.