A prospective study of the roles of clostridium difficile and enterotoxigenic Clostridium perfringens in equine diarrhoea.
Authors: Weese J S, Staempfli H R, Prescott J F
Journal: Equine veterinary journal
Summary
# Editorial Summary Weese and colleagues prospectively examined faecal samples from horses and foals with diarrhoea and healthy controls to establish the aetiological significance of *Clostridium difficile* and enterotoxigenic *Clostridium perfringens* in equine colitis. *C. difficile* isolation was substantially more prevalent in diarrhoeic animals (12.7% of affected adults, 35.5% of foals) compared to healthy controls (0.4% and 0% respectively), with toxins A and/or B detected in approximately one-fifth of affected adults and one-sixth of affected foals but rarely in controls. *C. perfringens* enterotoxin was found in nearly one-fifth of diarrhoeic adults and over a quarter of affected foals, yet was absent from normal faecal samples; notably, the positive predictive value of *C. perfringens* isolation for actual enterotoxin production was only 60–64%, and total spore counts showed no correlation with toxin presence. Adult horses that tested positive for *C. difficile* toxins experienced significantly poorer survival rates than toxin-negative colitis cases, suggesting this pathogen carries prognostic weight in clinical decision-making. These findings provide substantive evidence that both organisms warrant investigation in cases of equine enterocolitis, though practitioners should recognise that *C. perfringens* isolation alone is insufficient to confirm a pathogenic role without toxin confirmation.
Read the full abstract on PubMed
Practical Takeaways
- •Test faecal samples from horses with acute diarrhoea for C. difficile toxins and enterotoxigenic C. perfringens, as these pathogens are strongly associated with equine colitis and may guide treatment decisions
- •Presence of C. difficile toxins in diarrhoeic horses indicates a more serious prognosis; affected animals require closer monitoring and potentially more aggressive supportive care
- •Culture of C. perfringens alone is insufficient for diagnosis—toxin testing is essential as only 60-64% of isolated C. perfringens strains produce enterotoxin
Key Findings
- •Clostridium difficile was isolated from 12.7% of diarrhoeic adult horses and 35.5% of diarrhoeic foals, compared to 0.4% and 0% of normal animals respectively
- •C. difficile toxins A and/or B were detected in 21.8% of diarrhoeic adults and 16.7% of diarrhoeic foals versus 1.2% and 0% of normal animals
- •Enterotoxigenic C. perfringens was detected in 19% of diarrhoeic adults and 28.6% of diarrhoeic foals but absent in animals with normal faeces
- •C. difficile toxin-positive adult horses with colitis had significantly lower survival rates than toxin-negative horses (P = 0.03), with overall mortality of 22% in adults and 18% in foals