Hot Literature: Are antibiotics beneficial for treating hemorrhagic gastroenteritis?
We all know that inappropriate use of antibiotics in veterinary medicine is being ferreted out more and more since antimicrobial resistance is on the rise. Furthermore, inappropriate use of antibiotics can disrupt normal, protective intestinal flora and raise the risk for bacterial translocation and sepsis.
Idiopathic hemorrhagic gastroenteritis (HGE), one cause of acute hemorrhagic diarrhea in dogs, is often treated with antibiotics. However, the necessity for antimicrobial therapy has not been determined. Theories of bacterial translocation, bacterial causes, and the potential for sepsis have led to widespread use of antibiotics in dogs presenting with acute hemorrhagic diarrhea.
Amoxicillin/clavulanic acid, a commonly used antibiotic because of its broad spectrum and safety, is often a first-line choice in cases of HGE. A group of researchers in Germany have published the results of a study designed to evaluate whether treating dogs presenting with HGE with amoxicillin/clavulanic acid affects the clinical course or outcome.
Diagnostic tests included an abdominal ultrasonographic examination, serum chemistry profile, clotting profile, bile acid concentration measurement, fecal examination for parvovirus and parasites including Giardia species, and culture for enteropathogenic bacteria. Additionally, blood cultures were performed.
The dogs were randomly divided into either a placebo or treatment group. Dogs in the treatment group received amoxicillin/clavulanic acid for seven days. All other supportive therapies (fluids, antiemetics, gastric antacids, and disseminated intravascular coagulation prophylaxis) did not differ significantly between the two groups. Dogs were hospitalized for at least three days, and the antibiotic was administered by subcutaneous injection once daily (7 mg/kg) while the dogs were in the hospital and orally twice daily (12.5 mg/kg) after discharge. Dogs in the placebo group were given a placebo tablet at home.
The severity of clinical signs was evaluated based on a modified version of the canine inflammatory bowel disease index, ranking parameters such as attitude, appetite, vomiting, stool consistency and frequency, and dehydration. Scores ranged from 0 to 3, with 0 representing normal and 3 indicating severe clinical signs. The length of hospitalization and mortality rates was also compared between the two groups.
Study results and implications
Based on the results of this study, it would appear that HGE is not the result of a primary bacterial infection, the involved bacteria are not vulnerable to amoxicillin/clavulanic acid, or the bacterial infection or enterotoxin involved is self-limiting. Since the cause of HGE is unknown and it is often a diagnosis of exclusion, these findings suggest that further research is necessary to identify which patients may benefit from antimicrobial therapy and in which cases it is inappropriate.
Unterer S, Strohmeyer K, Kruse BD, et al. Treatment of aseptic dogs with hemorrhagic gastroenteritis with amoxicillin/clavulanic acid: a prospective blinded study. J Vet Intern Med 2011;25(5):973-979.