How can you recognize labor in a rat? - briefly
Observe nesting activity, frequent abdominal contractions, and the appearance of a swollen, reddened vulva with a visible birth canal opening; these signs typically precede delivery. Additional indicators include the presence of milk secretions and the expulsion of placental membranes shortly after pups are born.
How can you recognize labor in a rat? - in detail
Recognizing parturition in a laboratory rat requires observation of physiological and behavioral cues that reliably precede and accompany delivery.
Rats typically exhibit a distinct shift in activity patterns 12–24 hours before birth. The female becomes markedly restless, frequently rearranging bedding and constructing a nest. This nesting behavior intensifies as the expected time of delivery approaches.
Physical signs emerge shortly before the pups are expelled. A clear, milky vaginal discharge appears, often accompanied by a slight swelling of the vulva. Concurrently, the animal’s body temperature drops by 0.5–1 °C, detectable with a rectal probe or infrared thermometer. A gradual reduction in core temperature is a consistent predictor of imminent delivery.
Abdominal changes provide additional confirmation. Visible contractions of the uterus become apparent, and the abdomen may appear distended due to the growing litter. Palpation can reveal tightening of the uterine walls, especially during the final hours.
Hormonal assays, though not always practical in routine monitoring, can verify the onset of labor. Elevated prolactin and a sharp decline in progesterone levels are characteristic of the transition from gestation to parturition.
Post‑delivery observations solidify the diagnosis. The presence of a milk line on the mammary glands, the emergence of pink‑white secretions, and the rapid initiation of pup nursing indicate successful completion of labor.
Key indicators summarized:
- Increased nesting and restlessness, beginning 12–24 h before birth
- Milky vaginal discharge and vulvar swelling
- Drop in core body temperature (0.5–1 °C)
- Visible uterine contractions and abdominal distension
- Hormonal shift: high prolactin, low progesterone (if measured)
- Immediate post‑delivery signs: milk line, secretions, pup nursing
Systematic monitoring of these parameters enables accurate detection of parturition in rats, facilitating timely intervention and optimal welfare management.