Understanding the rationale for metronidazole use in dogs and cats

It is currently unknown how often antibiotics (including metronidazole) are used for non-antibacterial purposes in dogs and cats. This study looked to characterise the rationale for metronidazole prescription in these species.

Retrospective cohort study. Veterinarians reported clinical information for dogs and cats treated with metronidazole in the previous year, including the rationale for metronidazole selection.

Three hundred and thirty-two cases were reported by 138 veterinarians describing metronidazole use in 47 cats and 285 dogs. Metronidazole was most commonly prescribed to treat acute diarrhoea (n = 156, 47%), chronic diarrhoea (n = 79, 24%) or giardiasis (n = 36, 11%). Veterinarians selected metronidazole exclusively for non-antimicrobial targeted therapy in 42% of cases (125/300). Putative anti-inflammatory/immunomodulatory properties were cited in 64% of cases (213/332). Educational resources (41/92, 45%), team-based collaboration (29/92, 32%) and specialist consultation (10/92, 11%) were cited as the supportive basis for these prescription choices.

Veterinarians are using metronidazole frequently for non-antimicrobial properties in contradiction to antimicrobial use guidelines. Future stewardship programs should adapt guidance specifically to counter this prescribing behaviour.