Trust and professional relationships drive participation in passive cattle health surveillance among Dutch farmers and veterinarians.

Active involvement of farmers and veterinarians is crucial for the effectiveness of passive surveillance. This study aimed to identify the psychosocial factors influencing farmers' and veterinarians' decisions to contact a veterinary helpdesk or the competent authorities regarding cattle health concerns in the Netherlands. We used the COM-B model: for any Behavior (B) to occur, an individual must have the Capability (C), Opportunity (O), and Motivation (M) to perform it. Two separate surveys (for farmers or veterinarians) with Likert-scale statements informed by the COM-B behavioral framework were conducted. For a hypothetical herd of 100 cows, respondents were asked to indicate the weekly mortality threshold at which they thought they would contact a veterinarian, the helpdesk, or the competent authority. In total, 85 farmers and 63 veterinarians completed the survey. Farmers reported they intended to contact their veterinarian at 2.3 cattle deaths per week. Veterinarians indicated they would contact the helpdesk at 3.5 and the competent authority at 5.6 cattle deaths per week. An Exploratory Factor Analysis (EFA) of the farmer responses identified four psychosocial factors: "Farmer-veterinarian relationship," "Trust in institution," "Trust in peers and other professionals" and "Confidence." Regression models were used to examine the association between these psychological factors and reported helpdesk contact and stated mortality thresholds. The first three factors indicated that relational and trust-based factors appear to be important correlates of intended reporting behavior. Despite some variation in responses about the competent authority, no major barriers to engage in passive surveillance were identified. The small sample size and potential selection bias limit the generalizability of the results. Nevertheless, trust-based, low-threshold surveillance systems may improve early detection of animal threats through timely reporting.