How to check a rat's temperature? - briefly
Use a lubricated rectal thermometer sized for rodents, insert it about 0.5–1 cm into the anus, and wait a few seconds for a stable reading. An infrared sensor can provide a quick surface estimate, but rectal measurement gives the most reliable core temperature.
How to check a rat's temperature? - in detail
Measuring a rodent’s core temperature requires reliable equipment, gentle handling, and strict adherence to aseptic technique.
Essential tools
- Digital rectal thermometer with a flexible probe (0.5 mm diameter, calibrated to 0.1 °C)
- Sterile lubricant (e.g., veterinary-grade petroleum jelly)
- Disposable gloves
- Alcohol swabs
- Warm, quiet observation area (ambient temperature 22–24 °C)
- Record sheet or electronic log
Preparation
- Allow the animal to acclimate for at least 5 minutes in the observation area.
- Verify that the thermometer is clean, calibrated, and set to display Celsius.
- Apply a thin layer of lubricant to the probe tip.
- Wear disposable gloves and disinfect the probe with an alcohol swab before each use.
Rectal insertion method (gold‑standard)
- Gently restrain the rat by wrapping it in a soft towel, exposing the tail base while keeping the spine aligned.
- Insert the lubricated probe 2–3 mm into the anus, avoiding excessive force.
- Hold the probe steady for 30–60 seconds or until the temperature reading stabilizes.
- Record the value immediately; typical adult rat core temperature ranges from 37.5 °C to 38.5 °C.
- Remove the probe, disinfect it, and release the animal back to its cage.
Alternative non‑invasive techniques
- Infrared ear thermometer: Position the sensor at the ear canal opening; allow 10 seconds for equilibration. Accuracy may vary by ±0.5 °C.
- Surface infrared camera: Capture a thermal image of the dorsal region; interpret the hottest pixel as an estimate of core temperature, recognizing reduced precision.
Interpretation and follow‑up
- Values below 36.5 °C indicate hypothermia; above 39.0 °C suggest hyperthermia or fever.
- Repeat measurements at 15‑minute intervals if abnormal readings occur, and consult veterinary guidance if trends persist.
Safety considerations
- Use only sterile, single‑use probes or disinfect thoroughly between subjects.
- Minimize handling time to reduce stress‑induced temperature fluctuations.
- Ensure the animal’s tail remains warm to prevent peripheral vasoconstriction affecting readings.