Clostridium difficile associated diarrhoea in horses within the community: predictors, clinical presentation and outcome.

This research investigates the patterns, clinical manifestations, and outcomes of the horse disease, Clostridium difficile associated diarrhoea (CDAD), particularly within the community context. It primarily studies potential triggers and risk factors, the role of antimicrobial treatment, and disease’s development in horses.

Clostridium difficile and CDAD in Horses

• The bacterium Clostridium difficile is a common cause of hospital-acquired (nosocomial) and antimicrobial-association diarrhoea in humans. It is also a major contributor to colitis, an inflammation of the colon, in horses.
• Unlike for humans, for horses, this bacterium is not just a nosocomial pathogen; it is also associated with diseases prevalent in the wider horse community.
• The exact pathogenesis (mechanism of disease development) of CDAD is not fully understood. However, it is conjectured that the disruption of the indigenous gastrointestinal microflora (the community of microorganisms present in the digestive tract) is a significant trigger for CDAD.

Factors Influencing CDAD

• In human patients, the chief recognized risk factors for the development of CDAD are antimicrobial therapy and hospitalization. To a lesser extent, the administration of proton pump inhibitors, a type of medication used to reduce stomach acid, has also been linked.
• For horses, the connection between antimicrobial therapy and CDAD is less clear-cut. While antimicrobial therapy has been noted as a cause, it’s been suggested that CDAD mostly impacts horses undergoing antimicrobial treatment. However, the total influence of such treatments on equine CDAD is still unclear.
• Other peculiar developments include the incidence of CDAD in mares whose offspring are being treated with erythromycin. This occurrence has particularly been noted in Sweden.
• Proliferation of Clostridium difficile has been detected following the administration of penicillin to mature horses. Also, CDAD has been experimentally reproduced following erythromycin administration, even in low doses. Despite this, horses can still develop CDAD without undergoing antimicrobial therapy.

Evidence Gaps and Future Research

• No objective evaluation of the role of antimicrobial therapy, or other potential influencers, on equine CDAD has been reported. Thus, further research is called for to improve understanding of CDAD in the horse community, notably its triggers, risk factors, clinical presentation, and treatment outcomes.