Drivers and motivators of antimicrobial prescribing practices by veterinary surgeons and farmers in pig production in the United Kingdom

• Main Author: Coyne, L. A
• Format: Dissertation
• Language: English
• Published: University of Liverpool 2016
• DOI: 10.17638/03008102

Indiscriminate prescribing practices and the overuse of antimicrobials have been identified as a key driver for the emergence of antimicrobial resistant strains of bacteria in both humans and animals. Thus, it is essential that antimicrobial use practices are optimal and responsible to minimise these selection pressures. Antimicrobial use in pigs has been highlighted as an area of particular concern in the UK and Europe. The aims of this thesis were to provide a clear understanding of the motivations, practices, behaviours and attitudes surrounding the prescribing and use of antimicrobials in the UK pig industry, deemed an essential step optimising antimicrobial use. This thesis combines both qualitative and quantitative methodologies. Six initial focus group studies were held with pig veterinary surgeons (n=9) and farmers (n=17) to explore open-ended themes surrounding antimicrobial use and prescribing behaviours in pigs. The themes that emerged were explored in more detail using in-depth individual, face-to-face interviews with both farmers (n=22) and veterinary surgeons (n=21). A thematic approach was used for analysis. These results informed a quantitative questionnaire study which tested and explored key themes. The questionnaires were distributed to pig veterinary surgeons and farmers across England, Wales and Scotland. Results from 261 farmers and 61 veterinary surgeons were analysed using a predominantly descriptive approach, with analysis used to test the statistical significance of comparative respondent categories and multivariable logistic regression to explore risk factors for antimicrobial use on respondent farms. Additionally, open questions were analysed using a thematic approach. Most veterinary surgeons and farmers showed personal confidence that their own antimicrobial use was prudent and demonstrated a social responsibility to reserve the use of the critically important antimicrobial classes. However, many described clinical examples of the use of a critically important antimicrobial as a first line treatment, and farmer awareness of critically important antimicrobials was low. At odds with this sense of individual responsible use there was concern that antimicrobial use by other veterinary surgeons and farmers may be less responsible. The ‘habitual’ use of in-feed antimicrobials for disease prevention and use to overcome poor management were used to exemplify irresponsible use. Antimicrobial resistance was seldom cited as a clinical issue on farms, however there was dissonance in the perception of resistance on farms; both veterinary surgeons and farmers highlighted issues of treatment failures but could not, or did not, directly relate these to resistance. Additionally, whilst diagnostic testing, to identify causative agents and the most appropriate antimicrobial, were considered important their use was infrequently reported with financial implications and the time delay cited as reasons for this. Respondents expressed a desire to seek alternatives to prevent disease and decrease the use of antimicrobials such as improved internal and external biosecurity measures, more effective vaccination strategies, improved housing and improved herd health. However, the high cost required to make facility improvements coupled with the poor economic return on pig meat were commonly cited as a hurdle to reducing antimicrobial use on farms. Veterinary surgeons felt a major professional and moral obligation for animal health and welfare and this was also a recurring theme for farmers. It is clear that farmers and veterinary surgeons need to be able to make informed decisions to change and minimise antimicrobial use without compromising the health and welfare of animals under their care. There were contrasts in the way in which veterinary surgeons and farmers perceived their relationship; farmers identified a partnership where decisions are made mutually, whilst many veterinary surgeons identified pressure from clients to prescribe antimicrobials and some had concerns over poor farmer compliance in administering antimicrobials. The complexity surrounding prescribing decisions and use on farms suggests a combination of approaches is likely to be needed to ensure that antimicrobial prescribing is optimal and to achieve significant reductions in use.