Patterns of antimicrobial agent prescription in a sentinel population of canine and feline veterinary practices in the United Kingdom

14 Antimicrobial resistance is an increasingly important global health threat and the use of 15 antimicrobial agents is a key risk factor in its development. This study describes antimicrobial 16 agent prescription (AAP) patterns over a 2 year period using electronic health records (EHRs) 17 from booked consultations in a network of 457 sentinel veterinary premises in the United 18 Kingdom. A semi-automated classification methodology was used to map practitioner defined 19 product codes in 918,333 EHRs from 413,870 dogs and 352,730 EHRs from 200,541 cats, 20 including 289,789 AAPs. AAP as a proportion of total booked consultations was more frequent 21 in dogs (18.8%, 95% confidence interval, CI, 18.2-19.4) than cats (17.5%, 95% CI 16.9-18.1). 22 Prescription of topical antimicrobial agents was more frequent in dogs (7.4%, 95% CI 7.2-7.7) 23 than cats (3.2%, 95% CI 3.1-3.3), whilst prescription of systemic antimicrobial agents was more 24 frequent in cats (14.8%, 95% CI 14.2-15.4) than dogs (12.2%, 95% CI 11.7-12.7). A decreasing 25 temporal pattern was identified for prescription of systemic antimicrobial agents in dogs and 26 cats. Premises which prescribed antimicrobial agents frequently for dogs also prescribed 27 frequently for cats. AAP was most frequent during pruritus consultations


35
Antimicrobial resistance (AMR) is widely recognised as an increasingly important 36 global health threat. 1,2,3,4 Evidence of transmission of bacterial resistance amongst human 37 beings, livestock (Cuny et al., 2015) and companion animals 1 (Zhang, 2016) demonstrates the 38 necessity of a 'one health' approach to preserve treatment efficacy. 2 Although use of 39 antimicrobial agents selects for and promotes transfer of resistance (Rantala et al., 2004;40 Magalhaes et al., 2010;Cantón and Bryan, 2012), data on antimicrobial agent prescription 41 (AAP) to date are limited in animals.

42
Antimicrobial agents are frequently prescribed in dogs and cats (Mateus et al., 2011;43 Radford et al., 2011;Buckland et al. 2016), and there is evidence of development of resistance 44 in response to treatment 1 (Trott et al., 2004), and transmission of antimicrobial resistant isolates 45 between human beings and pets (Johnson et al., 2008a, b;Zhang et al., 2016). Specific guidance 46 for practice level prescription policies have been published 5,6 (Beco et al., 2013a, b); however, 47 there is a need to understand how these are being applied in practice. 48 Data on human AAP in the United Kingdom (UK) are freely available, in part because 49 of a national health system. 7 For animals, the Veterinary Medicines Directorate (VMD) is 50 constructing a central body collating data on AAP for the UK; however data currently available 51 cannot identify antimicrobial agents administered under the cascade prescribing system, which 52 species they have been prescribed to, practice level prescription variability or why the  and topical AAP as a proportion of total submitted consultations for each MPC. 99 random effects, was utilised to examine quarterly variation in total, systemic and topical canine 101 and feline AAP as a proportion of total consultations. The variable time was categorised as an 102 ordinal variable into quarters of the year (Q1, Q2, Q3 and Q4) and included as a fixed effect.

185
Broadly similar levels of total AAP were found in dogs and cats. However, when route 186 of administration was considered, dogs were significantly more likely to be prescribed topical 187 antimicrobial agents than cats, whereas cats were significantly more likely to be prescribed 188 systemic antimicrobial agents than dogs. Such differences may reflect an increased prevalence

192
Using data derived from EHRs, it was not possible to determine whether individual 193 prescriptions were appropriate, nor whether the overall frequency of AAP in this population 194 was appropriate. However, there was a significant reduction in canine and feline AAP within 195 this population over the 2 years of the study. Whether this reflects the success of awareness campaigns is not known. 14,15 It is possible that changes in AAP might reflect changes in other aspects of veterinary activity, such as vaccination. Furthermore, previous human AAP 198 surveillance has noted short-term temporal variability that is not necessarily reflective of longer 199 term patterns. 16 As a consequence, there is a need to for ongoing monitoring of AAP. where systemic antimicrobial agents were prescribed was 35.1% for dogs and 48.5% for cats.

205
In our study, these values were lower (unhealthy dogs 24.1%, unhealthy cats 30.5%). It is 206 unclear whether differences between these studies reflect a reduction in frequency of 207 prescription of systemic antimicrobial agents, or are related to population differences or 208 methods used to identify AAP.

209
Considerable variation in AAPs according to premise was identified in our study, as  Foundation. We wish to thank data providers both in veterinary practice (VetSolutions, Teleos, 283 CVS and non-corporate practitioners) and in veterinary diagnostics, without whose support and 284 participation this research would not be possible.