Clavulanate and cephalosporins: what is the cost of convenience?

Authors: Scarborough RD, Browning GF, Hardefeldt LY, Galgut BI, Marenda MS, Bailey KE
Publication: Australian Veterinary Practitioner, Volume 53, Issue 5, pp 209-219, Dec 2023
Publisher: Australian Veterinary Association

Article class: Clinical Article

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Abstract:

Background: The systemic antimicrobial given most often to Australian dogs is a potentiated penicillin, amoxicillin-clavulanate. Cats are most likely to receive a long-acting (14-day) injection of a third-generation cephalosporin, cefovecin, or amoxicillin-clavulanate. These antimicrobial choices are non-concordant with local and international empirical prescribing guidelines for common bacterial infections in dogs and cats.

Aims and Methods: We undertook quantitative analysis of culture and susceptibility (C&S) data from dog and cat samples sent to an Australian veterinary pathology laboratory, to evaluate the appropriateness of antimicrobial choices. We then conducted semi-structured interviews with 22 Australian veterinarians who treat dogs and cats, to understand their antimicrobial decisionmaking.

Results: C&S results from dog and cat urinary isolates showed that the vast majority (94%) of urinary pathogens tested could be treated with either amoxicillin or trimethoprim-sulfonamide, as recommended in prescribing guidelines. Amoxicillin-clavulanate was justified in just 4% of cases; cefovecin was never microbiologically justified. In both urinary and non-urinary isolates, adding clavulanate to amoxicillin was helpful in fewer than 1 in 10 cases. Interviews revealed significant modifiable barriers to guideline-concordant prescribing: lack of veterinarian awareness of guidelines and antimicrobial importance ratings, practices not routinely holding stock of guideline-recommended, low-importance antimicrobials, and veterinarians prioritising animals ‘finishing the course’ of antimicrobials over the more important consideration of choosing the best antimicrobial for the shortest effective duration.

Conclusions: Current antimicrobial use in companion animal practice is suboptimal and overuse of clavulanate and cephalosporins, particularly third-generation cephalosporins, puts animals and people at unnecessary risk. There are simple changes veterinarians can make to improve their antimicrobial prescribing.

Keywords: antimicrobial, antibiotic, importance, resistance, stewardship, small animal, pet, cat, dog, canine, feline, guidelines, prescribing, duration

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