EPI-DOM framework for assessing fish welfare: external and internal indicators for tilapia

Introduction: The EPI-DOM framework proposes an applied epidemiological approach to evaluate and manage tilapia welfare in laboratory and production systems, integrating animal-based indicators with risk factors organized into operational domains (management, environment, and interaction). Methods: An integrative review (2000-2025) was conducted and analytically structured under the EPI-DOM framework to: (i) classify external and internal indicators and define adverse welfare events (AWE); (ii) organize risk factors within the Management domain; and (iii) link indicators to risk factors through cross-mapping to prioritize interventions. Methodological criteria were incorporated for contextual interpretation of body integrity, physiological and biochemical ranges, harmonization of units/methods (for farms and laboratories), and the design of practical sampling schemes (population-level and sentinel) for farms. Results: The final product is an operational guide that translates dispersed evidence into a replicable welfare assessment system, including domain-based risk matrices, checklists, and preventive/corrective action guidance to identify critical welfare points and support context-specific decision-making. Discussion: EPI-DOM bridges welfare science and applied epidemiology by preserving traceability (indicator-risk-management-intervention), promoting comparability across systems, and allowing operational thresholds and sampling strategies to be adapted to local conditions without compromising methodological consistency. Conclusions: This EPI-DOM-aligned guide provides a dynamic, verifiable framework to support welfare improvement in tilapia, enabling evidence-based decision-making and implementation of good practices in both laboratory and field settings.