How can you tell that a rat has a fever? - briefly
Take a rectal temperature with a small‑animal thermometer; readings above 39 °C (102 °F) indicate fever. Supporting signs include lethargy, shivering and an unusually warm tail.
How can you tell that a rat has a fever? - in detail
Detecting an elevated body temperature in a rodent requires systematic observation and measurement. Visual cues, behavioral changes, and direct thermometry together provide reliable evidence.
Body temperature can be measured with a rectal probe designed for small mammals. Lubricate the probe, insert it gently 1–2 cm into the anus, and record the reading after stabilization. Normal murine core temperature ranges from 36.5 °C to 38 °C; values consistently above this interval indicate pyrexia.
If invasive measurement is impractical, indirect signs help assess the condition:
- Reduced activity – prolonged immobility, reluctance to explore, or diminished grooming.
- Altered posture – hunching, tucked limbs, or a flattened back.
- Respiratory changes – faster, shallow breaths or audible wheezing.
- Skin temperature – cooler extremities when the core is hot, detectable by gentle touch.
- Appetite loss – decreased consumption of food or water for more than 12 hours.
- Weight loss – measurable decline over a short period.
Thermal imaging cameras can capture surface temperature variations without handling the animal. Elevated infrared emissions from the torso, especially when contrasted with the limbs, suggest internal heat rise.
For laboratory settings, combine methods: perform a rectal temperature check to confirm fever, then monitor the above behavioral and physiological indicators to track progression and response to treatment. Consistent documentation of each parameter ensures accurate diagnosis and facilitates reproducible research outcomes.