How to measure a mouse's temperature? - briefly
Use a fine‑gauge rectal thermistor probe inserted 2–3 mm into the anal canal, allowing the reading to stabilize before recording. A calibrated infrared sensor aimed at the ear or tail offers a rapid, non‑invasive alternative.
How to measure a mouse's temperature? - in detail
Accurately determining a rodent’s core temperature requires selecting an appropriate technique, preparing the animal, and using calibrated equipment. The most common methods are rectal thermometry, infrared thermography, and implanted telemetry probes.
Rectal thermometry provides rapid, reliable readings for short‑term studies. Use a digital veterinary thermometer with a flexible, lubricated probe no larger than 2 mm in diameter. Restrain the mouse gently with a soft cloth or a dedicated restrainer to prevent movement. Insert the probe 2–3 mm into the anal opening, wait until the display stabilizes (typically 5–10 seconds), then record the value. Clean the probe with alcohol between animals to avoid cross‑contamination.
Infrared thermography measures surface temperature without contact, useful for repeated measurements or when stress must be minimized. Position a calibrated infrared camera at a fixed distance (10–15 cm) from the dorsal region. Ensure the environment is thermally stable (22 ± 1 °C) and eliminate drafts. Capture an image, then analyze the region of interest using the camera’s software to obtain the temperature. Surface readings correlate with core temperature only after establishing a conversion factor through simultaneous rectal measurements.
Implanted telemetry offers continuous, high‑resolution data for long‑term experiments. Select a miniature, sterile temperature probe (e.g., 1.5 g, 2 mm diameter) compatible with a wireless transmitter. Perform aseptic surgery under anesthesia, placing the probe intraperitoneally or subcutaneously. Secure the transmitter to the dorsal musculature, close the incision, and allow a recovery period of 5–7 days before data collection. The system transmits temperature readings to a receiver at preset intervals (e.g., every minute). Verify probe accuracy periodically by comparing against a calibrated rectal thermometer.
Key considerations for all techniques:
- Calibration: Verify thermometer or camera accuracy daily with a certified reference standard.
- Animal welfare: Limit handling time, use appropriate anesthesia for invasive procedures, and monitor for stress indicators.
- Environmental control: Maintain consistent ambient temperature and humidity; avoid direct sunlight or cold drafts during measurements.
- Data consistency: Record the time of day, animal’s activity state, and any recent handling to account for physiological fluctuations.
By following these protocols, researchers can obtain precise temperature measurements that support reliable physiological and pharmacological assessments in mice.