Project <scp>WORMS</scp> (working to overcome resistance and make for a sustainable future): Horse owner survey on equine parasite control in the <scp>UK</scp>. Part 1. Management factors

Summary Background Anthelmintic resistance in equine parasites is increasing. Pasture management is a vital component of helminth control; its implementation is key to reducing anthelmintic dosing frequency to reduce selection pressure for resistance. Objectives To investigate how horse owners use management procedures to control common intestinal parasites in horses. Study design Cross‐sectional study conducted through an online questionnaire of UK horse owners. Methods The questionnaire (combination of multiple choice, Likert scale and free‐text questions) was distributed via practices, equestrian organisations, etc., from December 2021 to October 2022. Respondents were asked about pasture management, diagnostic testing and worm‐associated illnesses. Descriptive and inferential statistics were performed in Microsoft Excel and IBM SPSS. Results There were 4232 usable responses. Only 21.5% of respondents alternated or co‐grazed their horse with ruminants (higher for horses grazing on private properties compared to horses grazing on livery yards; p &lt; 0.001). The majority of owners (73.3%) removed faeces from pastures (poo‐picking), of which 86.4% removed faeces twice a week or more. Owners of horses pastured individually were more likely to poo‐pick (89.8%) than horses pastured in groups (68.9%; p &lt; 0.001). The majority of respondents (77.1%) rested pastures, but less than 5% for over 6 months. Only 5.1% of owners reported they had experienced illnesses related to worms in any horse (commonest clinical signs were colic and weight loss). Main limitations Risk of selection bias and social desirability bias. Some aspects of pasture management (e.g. stocking density) were not included. Horse owners were asked to complete the questionnaire for one horse only. Conclusions Many owners (&gt;25%) are not routinely poo‐picking, and the majority are not co/alternate grazing or resting pastures effectively, identifying opportunities to improve parasite control. Optimising management practices should reduce the requirements for using anthelmintics to achieve parasite control, thereby reducing selection pressure on the development of resistance.