These data are associated with the WORMSS project (Worms - Resistance and Moxidectin on Scottish Sheep Farms) conducted during 2020 at the University of Glasgow in association with Flock Health Ltd and collaborating with Queen's University Belfast. The data were written up in a paper published in the Veterinary Record; "Moxidectin use in Scottish sheep flocks suggests a need for clearer product labelling and communication of updated SCOPS guidelines", McIntyre, J. et al 2022 Data includes: 1. Two questionnaires sent generally to farmers (Part A). 2. Two questionnaires provided to farmers who had collected sheep faecal samples post-moxidectin treatment (Part B). 3. Questionnaire data in two excel files: WORMSS Part A - the data collected from farmers across Scotland, and from outside of Scotland. Concerns information regarding moxidectin and other anthelmintic use generally in flocks. The data has been partially cleaned and all personal information removed so that it is anonymised. WORMSS Part B - data collected from farmers across Scotland who had chosen to send in post-moxidectin treatment samples. Contains more detailed information as to their use of moxidectin in their flocks and worm management. 4. Faecal egg count and summarised species information for sheep faecal samples sent in from farms across Scotland by farmers following treatment of their sheep with moxidectin in 2020. Each farm sent in two sets of samples; one 2-3 weeks post-treatment and another towards the end of the persistency period of the product used.