Use of antimicrobials licensed for systemic administration in UK equine practice

Abstract

BackgroundJudicious antimicrobial use (AMU) is important for preserving therapeutic effectiveness. Large‐scale studies of antimicrobial prescribing can provide clinical benchmarks and help identify opportunities for improved stewardship.ObjectivesTo describe systemic AMU in UK equine practice and identify factors associated with systemic and Category B (third and fourth generation cephalosporins, quinolones and polymixins) AMU.Study designRetrospective cohort.MethodsAnonymised electronic patient records (EPRs) for all equids attended by 39 UK veterinary practices between 1 January and 31 December 2018 were collected via the VetCompass programme. Systemic antimicrobial prescriptions were identified using electronic keyword searches. Indications for AMU were determined through manual review of a randomly selected subset of EPRs. The types and frequency of systemic antimicrobials prescribed and indications were summarised using descriptive statistics. Mixed‐effects logistic regression was used to evaluate practice‐ and horse‐related risk factors.ResultsSystemic antimicrobials were prescribed to 12 538 (19.5%, 95% confidence interval [CI]: 19.2%–19.8%) of 64 322 equids attended in 2018. Category B antimicrobials were prescribed to 1.9% (95% CI: 1.8%–2.0%) of attended equids and in 8.9% (95% CI: 8.5%–9.4%) of antimicrobial courses. Bacteriological culture was performed in 19.1% (95% CI: 17.1%–21.3%) of Category B antimicrobial courses. The most commonly prescribed antimicrobial classes were potentiated sulphonamides (50.2% of equids receiving antimicrobials) and tetracyclines (33.5% of equids receiving antimicrobials). Integumentary disorders were the most common reason for systemic AMU (40.5% of courses). Urogenital disorders were the most common reason for Category B AMU (31.1% of courses). Increased odds of systemic and Category B AMU were observed in equids <1 year compared with those aged 5–14 years. Breed was associated with AMU, with odds of systemic and Category B AMU highest in Thoroughbreds and Thoroughbred crosses.Main limitationsConvenience sample of practices may limit generalisability.ConclusionsEmpirical use of Category B antimicrobials remains commonplace.

Antimicrobial prescribing and antimicrobial resistance surveillance in equine practice

“…A recent study examining electronic patient records (EPRs) for all equids attended by five UK equine practices reported that HPCIA antimicrobials were prescribed in 8.2% of antimicrobial courses. 14 The most commonly reported indication in this study for use of 3rd or 4th generation cephalosporins was in foals. Neonatal sepsis has been most associated with gram negative infection, although the incidence of gram-positive infection is increasing.…”

“…18 More recent UK data using EPRs from equine practices in 2016-2017 showed that HPCIA antimicrobials were prescribed in 8.2% of courses and were used without prior C&S in 80.7% of courses. 14 This study highlights the frequent use of antimicrobials which are not currently authorised for use in the UK. In some clinical scenarios, these may be considered a first-line choice with consideration to antimicrobial susceptibility and responsible use, which highlights the importance of practice policies or treatment guidelines.…”

“…47 The Royal College of Veterinary surgeons (RCVS) has a voluntary Practice Standards Scheme (PSS) 47 with levels reported by retrospective analysis of EPRs in the US and UK. 14,18,22 In summary, this paper describes current antimicrobial prescribing in equine practice. It indicates an apparent reduction in use compared with previous studies with an increase in antimicrobial use policies in practice.…”

“…In the fourth clinical scenario (colitis), respondents advised treatment with ceftiofur, enrofloxacin or polymyxin B in 11.5% of responses where antimicrobials were prescribed. A recent study examining electronic patient records (EPRs) for all equids attended by five UK equine practices reported that HPCIA antimicrobials were prescribed in 8.2% of antimicrobial courses 14 …”

Highlights of recent clinically relevant papers

“…This retrospective study by Sarah Allen and UK‐based co‐workers aimed to describe systemic antimicrobial use (AMU) in UK equine practice and identify factors associated with systemic and Category B AMU .…”