Disease surveillance in laboratory animal colonies protects both individual animal welfare and research validity, and sentinel animal programs provide ongoing monitoring between colony health assessments.
Colony disease surveillance is a welfare protection system that operates preventively — identifying pathogen introduction before disease becomes clinically apparent and welfare-compromising. Animals with subclinical infections experience immune system activation that represents a welfare cost even without obvious signs, and alters their physiology in ways that confound experimental results. The sentinel animal program is itself a welfare consideration: sentinel animals are deliberately exposed to potentially infected bedding and monitored for immune responses. Their welfare depends on prompt detection and appropriate management when infections are identified. Colony depopulation following uncontrolled outbreak causes the loss of many individual animal lives — a welfare and resource catastrophe that rigorous surveillance prevents. Investment in surveillance infrastructure and training is therefore directly welfare-protective at colony scale.