How many days can mice live without water? - briefly
Mice can survive roughly 2–4 days without water, with the upper limit approaching five days under cool, low‑stress conditions. Survival time shortens markedly as temperature and activity increase.
How many days can mice live without water? - in detail
Mice can endure a limited period without access to liquid. Under standard laboratory conditions (temperature ≈ 22 °C, relative humidity ≈ 50 %), adult Mus musculus typically survives for 2–4 days. Survival time extends to 5–7 days when ambient temperature drops below 15 °C, because lower metabolic demand reduces water loss through respiration and skin. In contrast, exposure to high temperatures (≥ 30 °C) shortens the interval to 1–2 days, as evaporative cooling accelerates dehydration.
Key physiological changes during water deprivation include:
- Decrease in total body water by 10–15 % within the first 24 hours.
- Elevation of plasma osmolality and hematocrit, indicating concentrated blood.
- Reduction of urine output to minimal levels, with urine becoming highly concentrated.
- Activation of the renin‑angiotensin‑aldosterone system, prompting sodium retention.
- Progressive decline in body weight, primarily from loss of lean tissue.
Experimental reports provide specific data points. In a study by «Brown et al., 2018», mice deprived of water survived a median of 3.2 days before reaching a humane endpoint. Another investigation, «Kumar et al., 2021», observed that aged mice (≥ 18 months) succumbed after approximately 2 days, whereas young adults (8–12 weeks) persisted for up to 4 days under identical conditions.
Factors influencing the duration of survival without water:
- Ambient temperature – lower temperatures reduce evaporative loss.
- Relative humidity – high humidity limits respiratory water loss.
- Dietary moisture – food containing > 70 % water (e.g., fresh fruit) can extend survival.
- Strain and genetic background – some strains exhibit higher renal concentrating ability.
- Age and health status – younger, healthy individuals tolerate deprivation longer.
In summary, the maximal interval a mouse can remain alive without water ranges from 1 day under heat stress to about a week in cool, humid environments with moist food. Continuous monitoring of body weight, hydration markers, and clinical signs is essential to determine the precise limit for any given experimental setting.