Doctoral Dissertations

Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Comparative and Experimental Medicine

Major Professor

Chika Okafor

Committee Members

Marc Caldwell, J. Mark Fly, Agricola Odoi


Antimicrobial drugs are used for maintaining or improving animal health. Non-judicious antimicrobial use (AMU) is a modifiable factor driving antimicrobial resistance (AMR). Using qualitative and quantitative approaches, this doctoral dissertation examined the epidemiology of veterinary AMU among clinicians at The University of Tennessee Veterinary Medical Center (UTVMC), and cattle producers in Tennessee (TN), and identified strategies for antimicrobial stewardship (AMS). First, an online survey was sent to UTVMC clinicians to identify factors influencing their AMU practices, analyze their concerns regarding AMU and AMR. Compared to clinicians who obtained their veterinary degree from 1970–1999, those who graduated from 2000–2009 and 2010–2016 were 3.96 (P = 0.034) and 5.39 (P = 0.01) times less concerned about AMR, respectively. Second, a qualitative study was undertaken to identify and document the factors driving AMU, alternatives, knowledge, and perceptions towards AMU among TN beef cattle producers. The findings suggested that clinical signs, culture & susceptibility testing drive AMU and more awareness of drivers for AMR, and continuing education for producers on prudent AMU is needed. Third, a mixed methods study that was conducted with TN dairy producers showed that use of culture and sensitivity test results for antimicrobial selection was a widespread and common practice, and blanket dry cow therapy was still commonly practiced. Fourth, a survey of TN beef cattle producers was conducted to identify the factors driving their AMU, as well as their alternatives, knowledge, and perceptions towards AMU. The findings showed that controlling for type of cattle operation, age was significantly associated with the producer’s degree of concern about AMR (P = 0.022). Additionally, survey findings suggested a need to promote the use of written antimicrobial treatment protocols among TN beef producers, and continued training for producers on infection prevention/control and prudent AMU. Fifth, a mixed methods study was conducted to identify the perceptions of TN cattle producers regarding the Veterinary Feed Directive. The findings suggested a likely compensatory increase in the use of injectable antimicrobials for therapeutic and prophylactic purposes that should be further investigated. Overall, the entire project identified key strategies for improving AMU in TN.

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