The use of metronidazole in adult dogs with acute onset, uncomplicated, diarrhoea

Emma Rogers-Smith

doi:10.18849/ve.v6i4.445

Abstract

PICO question In adult, non-geriatric, dogs with acute onset (<7 days duration) uncomplicated diarrhoea does the addition of metronidazole to a supportive care protocol such as dietary modification or probiotics (excluding other antimicrobials) reduce the time to resolution of diarrhoea compared to supportive care protocols alone?  Clinical bottom line Category of research question Treatment The number and type of study designs reviewed Four studies were included in this appraisal. Two prospective, double blinded, placebo controlled clinical trials, one prospective treatment trial and one retrospective longitudinal observational study Strength of evidence Weak Outcomes reported One study found a shortened duration of clinical signs (by 1.5 days; p = 0.04) in the metronidazole treated group compared to control. However, a separate study found no significant difference between control and metronidazole groups in the regards to resolution of clinical signs. One study demonstrated a long standing (>28 day) negative impact of metronidazole treatment on gut microbiome with no difference in time to resolution of clinical signs when compared with faecal matter transplant Conclusion The current evidence for the superiority of metronidazole compared to supportive treatment alone is weak and at this time there is no evidence-based rationale for its use in cases of uncomplicated, acute, canine diarrhoea. Furthermore, the negative implications of metronidazole on the intestinal microbiome have been found to be long standing (>28 days as a minimum) and should not be discounted by the prescribing clinician  How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care. 

Highlights

Main findings:: Dogs were withdrawn from the study due to owner non-compliance, abnormalities noted on post-enrollment laboratory or polymerase chain reaction (PCR) testing or high faecal worm egg count Patient age:
Significant difference between acute diarrhoea dogs compared to healthy controls
Time until resolution of diarrhoea significantly associated with treatment group in multivariable analysis. o Time to resolution of clinical signs 1.5 day shorter in metronidazole group (p = 0.04)

Summary

Conclusion

The current evidence for the superiority of metronidazole compared to supportive treatment alone is weak and at this time there is no evidence-based rationale for its use in cases of uncomplicated, acute, canine diarrhoea. Knowledge Summaries are a resource to help reinforce or inform decision making. The evidence Until as recently as 2019 the evidence basis for the use of metronidazole in the face of uncomplicated acute canine diarrhoea (UACD) and its superiority to supportive treatment alone (dietary modification, probiotics and more recently faecal matter transplant) has been anecdotal. The evidence for the PICO question was found to be weak and at this time there is insufficient evidence to suggest metronidazole is superior in reducing the duration of clinical signs of UACD when compared to supportive measures alone

Summary of the evidence

Limitations:

Findings

Methodology Section