How long can a mouse live without food? - briefly
A mouse typically endures about 2–4 days without nourishment, depending on its age, health status, and ambient temperature. If water is also absent, mortality occurs within 24–48 hours.
How long can a mouse live without food? - in detail
A mouse can endure a period without caloric intake, but the exact length depends on species, age, body condition, ambient temperature, and hydration status. Laboratory studies on standard laboratory strains (e.g., C57BL/6) show that a healthy adult can survive approximately 2 to 3 days without food when water remains available. Survival beyond 48 hours typically involves rapid depletion of glycogen stores, followed by reliance on fat reserves and, later, protein catabolism.
Key physiological stages during food deprivation:
- Glycogen depletion (0–12 h): Liver glycogen supplies glucose for the brain and red blood cells.
- Lipolysis (12–48 h): Fat stores are mobilized, producing ketone bodies that become the primary cerebral fuel.
- Protein catabolism (>48 h): Muscle protein is broken down to supply gluconeogenic substrates; this accelerates weight loss and impairs organ function.
Factors that modify the survival window:
- Ambient temperature: Cooler environments reduce metabolic rate, extending the fasting period by up to 30 %.
- Body fat percentage: Heavier mice with greater adipose tissue can sustain energy production longer.
- Age: Juvenile mice possess limited glycogen and fat reserves, shortening survivable fasting time to roughly 24 hours.
- Hydration: Access to water is critical; dehydration can cause death within 24 hours, regardless of caloric status.
- Strain genetics: Certain inbred strains exhibit metabolic efficiencies that alter fasting tolerance.
Experimental observations indicate that, when both food and water are withheld, mortality typically occurs within 12–24 hours. Conversely, continuous water supply permits survival up to 72 hours, after which severe hypoglycemia, hypothermia, and organ failure become inevitable.
For ethical laboratory practice, standard protocols require provision of food or water at least every 24 hours to prevent undue suffering. Monitoring includes daily weight measurement, assessment of coat condition, and observation of activity levels to detect early signs of distress.
In summary, a mouse can survive without nourishment for roughly two to three days if water is available, with the precise limit shaped by environmental conditions, physiological reserves, and genetic background. Beyond this interval, critical metabolic failure leads to rapid mortality.