Quantification of topical antimicrobials in Dutch companion animal veterinary clinics: Developing and evaluating a quantification method.

Abstract

ABSTRACT

Background: Topical antimicrobial (TAM) preparations are used extensively in human and companion animal medicine. Alterations in the bacterial flora of the treated area and emergence of resistant strains has been reported in humans, consequently to topical antimicrobial use (AMU). Resistant strains of staphylococci have also been isolated in companion animals and a reduction in the efficacy of these TAMs is of concern. Exposure to TAMs during their application by pet owners may be additionally hazardous to the owners due to toxic or adverse reactions to the drugs. Quantifying topical AMU in companion animal medicine could aid in the surveillance of antimicrobial resistance emergence and in determining the necessity of intervention strategies. Gaining more insight on topical AMU might also optimize dosing regimens, thus ensuring positive patient outcomes.

Objective: The main objective of this study was to develop a quantification method, which could be used to quantify the use of TAMs in companion animal veterinary clinics and describe the topical AMU in 44 Dutch companion animal veterinary clinics.

Method: This study consisted of four successive stages. In the first and second stage of the study, a literature review was conducted to identify possible quantification methods and their advantages and disadvantages were explored using a sample dataset. The third stage consisted of an experts’ meeting, aiming to arrive at the final quantification method by consensus. Ultimately, the chosen quantification method was applied to a dataset containing monthly prescription data from 44 Dutch companion animal veterinary clinics and the seasonality, time trends and possible determinants of topical AMU were explored using statistical modelling.

Results: The Defined Daily Dose for Animals (DDDA) quantification method was deemed as a suitable method to quantify the use of TAMs in companion animal veterinary clinics. A seasonal effect was found, suggesting that the total use of TAMs was highest in the months July-August and lowest in the months February-March. A significant decrease over time concerning total topical AMU was also observed. The proportion of dogs in the clinic appeared to affect the topical AMU. Clinics with a larger proportion of dogs had significantly higher total, first and second choice topical AMU. Likewise, ear and skin preparations were used significantly more in these clinics.

Conclusions: This study displayed that the DDDA method is a suitable quantification method to quantify topical AMU. The analysis of retrospectively acquired data from 44 Dutch companion animal veterinary clinics in a three-year period (2012-2015) showed the existence of a seasonal effect and a decrease in topical AMU over time. The DDDA method should be better standardized for topical AMU in the future and the intervention effect on topical AMU should be further explored.