How much water does a mouse need? - briefly
A mouse typically drinks about 3–5 ml of water each day, with intake varying by body weight, diet moisture content, and ambient temperature. Supplying fresh water daily prevents dehydration and maintains normal physiological processes.
How much water does a mouse need? - in detail
A mouse typically consumes between 3 ml and 7 ml of water per 100 g of body weight each day. For an adult laboratory mouse weighing 20–30 g, daily intake ranges from 0.6 ml to 2.1 ml. The exact volume depends on several variables that influence metabolic demand and evaporative loss.
- Ambient temperature: higher temperatures increase respiratory and skin evaporation, raising fluid requirements.
- Relative humidity: low humidity accelerates water loss through the respiratory tract.
- Diet composition: high‑protein or high‑salt feeds raise renal excretion, prompting greater drinking.
- Activity level: more locomotion or thermogenic activity elevates metabolic rate and fluid turnover.
- Age and health status: juveniles and sick animals may have altered thirst mechanisms.
In controlled environments, researchers often provide water ad libitum through calibrated bottles, ensuring that consumption can be recorded. Typical measurement protocols involve weighing bottles before and after a 24‑hour period, correcting for spillage. Data from such studies show an average intake of 1.5 ml per day for a 25‑g mouse kept at 22 °C with 50 % relative humidity and standard chow.
For pet mice, water should be offered continuously in a clean, spill‑proof dispenser. Monitoring daily consumption helps detect dehydration early. Signs of insufficient hydration include sunken eyes, dry skin around the nose, reduced urine output, and lethargy. If intake falls below 0.5 ml per day for a 25‑g mouse, supplemental fluids—either via a syringe or a moist diet—should be administered promptly.
In summary, the fluid requirement of a mouse is modest but highly sensitive to environmental and physiological factors. Providing unrestricted access to fresh water, maintaining stable temperature and humidity, and regularly tracking intake are essential practices for ensuring optimal hydration.