TABLE 1.

Commonly used measures of well-being for laboratory mice

Biologic process	Test methodology	Parameters tested	Rationale
Behavior: aggression, anxiety, distress	Open field arena	Time spent in center vs. periphery	Exploration; may reveal anxiety. Anxious mice are thought to spend less time in center
	Light/dark box	Time spent and mobility in light or dark side of a box	Exploration; may reveal anxiety. Anxious mice are thought to spend less time in light side
	Tail suspension test	Time to immobility	Measures chronic or induced despair/depression; longer time to immobility suggests more despair
	Elevated plus maze	Time spent in open or closed arms	Measures anxiety; more time spent in closed arms suggest anxiety
	Home cage monitoring: automated or observational	Fighting, bite or scratch wounds, social behaviors	Increased aggression may be due to chronic social stress
	Hormone measurements	Corticosterone, testosterone	Stress is indicated by increased production of stress hormones
	Organ weight	Adrenal glands, testes	Increased organ weight due to increased production of stress hormones
Immune function	Organ weight	Spleen, thymus	Increased weight due to increased production of immunologic factors or stress hormones
	Flow cytometry	T-cell subpopulations	Immunologic status may change with chronic stress
	Hematology	Complete blood counts	General well-being
Cardiovascular	Electrocardiogram, blood pressure, telemetry	Heart rate	Increases with increasing stress
	Organ weight	Heart weight	May increase with increased chronic stress
Reproduction	Breeding success	Litter size, time between litters, number of litters	Small litters and increased time between litters may indicate distress
	Litter success	Pup weight, survival, play behavior, press posture, mortality	Viability of pups reflects behavioral environment
General health	Growth	Body weight increase with development	Abnormal weight patterns may reflect social stress
	Body composition (e.g., DEXA)	Fat tissue mass, bone mineral density	Chronic stress mice may inhibit body fat accumulation and reduce bone density
	Food and water consumption	Daily or weekly intake	Abnormal eating or drinking patterns may reflect social stress
	Mortality	Number and timing of deaths	Failure to thrive may reflect social stress
	Clinical chemistries	Plasma lipids, glucose	General well-being
	Cage microenvironment (air quality)	CO2, NH3, temperature, relative humidity; nasal pathology	Poor cage air quality compromises well-being; nasal pathology reflects deleterious effects of high concentrations of inhaled irritants