Treatment of Aseptic Dogs with Hemorrhagic Gastroenteritis with Amoxicillin/Clavulanic Acid: A Prospective Blinded Study

Background: Antibiotics generally are recommended to treat hemorrhagic gastroenteritis (HGE). Inappropriate use of antibiotics may promote risk of antimicrobial resistance and unnecessary adverse drug reactions. The necessity of antimicrobial therapy in dogs with HGE has not been demonstrated. Objective: The purpose of this prospective, placebo-controlled, blinded study was to evaluate whether treatment with amoxicillin/clavulanic acid improves the clinical course and outcome of HGE in dogs that show no signs of sepsis. Animals: The study included 60 dogs diagnosed with HGE between 2007 and 2009 at the Clinic of Small Animal Medicine, LMU University of Munich, Germany. The inclusion criterion was the presence of acute hemorrhagic diarrhea (<3 days). Dogs pretreated with antibiotics, with signs of sepsis, or diagnosed with any disease known to cause bloody diarrhea were excluded from the study. Methods: Patients were randomly divided into treatment (amoxicillin/clavulanic acid for 7 days) and placebo groups. To evaluate treatment efficacy, severity of clinical signs (based on a newly developed HGE index), duration of hospitalization, and mortality rate were compared between the 2 groups. Results: Fifty-three of 60 dogs completed the study. No significant difference between treatment groups concerning mortality rate, dropout rate, duration of hospitalization, or severity of clinical signs, either on any individual day or over the course of disease, was observed. Conclusions and Clinical Importance: In some dogs with HGE that show no signs of sepsis, antibiotics may not change the case outcome or time to recovery.