Conceptual model to predict dairy farmers’ adoption of diagnostic methods for control of gastrointestinal nematode infections, based on the work by Vande Velde et al. (2015), and extended with insights from previous decision-making frameworks for parasite control. Notes. Full lines represent the equations informed by Vande Velde et al. (2015), dotted lines by Rose Vineer et al. (2017), short-dashed lines by Mingolla et al. (2019), dashed-dotted lines by Vande Velde et al. (2018). The following factors are included: Perceived knowledge (i.e., perception of the current knowledge one has on the context of control of gastrointestinal nematode infections); Perceived control (i.e., perceived ability to adopt diagnostics for control of gastrointestinal nematode infections); Routine (i.e., perception of the current treatment); Attitude diagnostics (i.e., evaluation of the expected outcomes to adopt diagnostics for control of gastrointestinal nematode infections); Attitude anthelmintics (i.e., evaluation of the expected outcomes to preventively treat with anthelmintics for control of gastrointestinal nematode infections); Descriptive norms (i.e., perception of peers that actually perform a diagnosis for control of gastrointestinal nematode infections); Subjective norms (i.e., perception of the expectation of significant others in performing a diagnosis for control of gastrointestinal nematode infections); Perceived susceptibility (i.e., perception of the vulnerability to anthelmintic resistance); Perceived severity (i.e., perception of the impact of anthelmintic resistance); Behavioural intention (i.e., intention to adopt diagnostics for control of gastrointestinal nematode infections); and Behaviour (i.e., self-reported adoption of diagnostics for control of gastrointestinal nematode infections).