Infectious agents detected in the feces of diarrheic foals: a retrospective study of 233 cases (2003-2008)

Abstract

Background: Diarrhea is common in foals but there are no studies investigating the relative prevalence of common infectious agents in a population of hospitalized diarrheic foals.

Objectives: To determine the frequency of detection of infectious agents in a population of hospitalized foals with diarrhea and to determine if detection of specific pathogens is associated with age, outcome, or clinicopathologic data.

Animals: Two hundred and thirty-three foals < or = 10 months of age with diarrhea examined at a referral institution.

Methods: Retrospective case series. Each foal was examined for Salmonella spp., viruses, Clostridium difficile toxins, Clostridium perfringens culture, C. perfringens enterotoxin, Cryptosporidium spp., and metazoan parasites in feces collected at admission or at the onset of diarrhea.

Results: At least 1 infectious agent was detected in 122 foals (55%). Rotavirus was most frequently detected (20%) followed by C. perfringens (18%), Salmonella spp. (12%), and C. difficile (5%). Foals < 1 month of age were significantly more likely to be positive for C. perfringens (odds ratio [OR] = 15, 95% confidence interval [CI] = 3.5-66) or to have negative fecal diagnostic results (OR = 3.0, 95% CI = 1.7-5.2) than older foals. Foals > 1 month of age were significantly more likely to have Salmonella spp. (OR = 2.6, 95% CI = 1.2-6.0), rotavirus (OR = 13.3, 95% CI = 5.3-33), and parasites (OR = 23, 95% CI = 3.1-185) detected compared with younger foals. Overall 191 of the 223 foals (87%) survived. The type of infectious agent identified in the feces or bacteremia was not significantly associated with survival.

Conclusions and clinical importance: In the population studied, foals with diarrhea had a good prognosis regardless of which infectious agent was identified in the feces.

Figure 1

Age of foals with diarrhea according to the results of fecal diagnostic testing. None indicates that all testing was negative. The central box represents the values from the lower to upper quartile (25th–75th percentile). The middle line represents the median. The vertical line extends from the minimum to the maximum value, excluding outliers (lower or upper quartile ± 1.5 times the interquartile range), which are displayed as separate points. ^a,bDifferent letters between groups indicate a significant difference in age (P < .05). When at least 1 letter is common between groups, the difference is not statistically significant.