How to determine that a rat is about to give birth? - briefly
Look for nesting activity, a markedly swollen abdomen, and a clear vaginal discharge, all of which signal that the female is near parturition. Additionally, the vulva will appear pink and enlarged, and the rat often shows increased restlessness.
How to determine that a rat is about to give birth? - in detail
Female rats display a predictable set of physical and behavioral changes as parturition approaches. Recognizing these signs enables timely preparation of a safe environment for the litter.
The abdominal cavity expands noticeably during the final days of gestation. The belly becomes rounder and firmer, with the uterus visible through the skin. Swelling of the mammary glands occurs concurrently; the nipples enlarge and may darken, indicating milk production is beginning.
Vaginal discharge appears 24‑48 hours before delivery. The fluid is typically clear to slightly milky and may be accompanied by a mild odor. Observing any wetness around the perineal area signals that labor is imminent.
Body temperature drops by approximately 1–2 °C (1.5–3.5 °F) within 12 hours of birth. Measuring the rat’s temperature with a rectal probe or infrared thermometer provides a reliable physiological indicator.
Nesting behavior intensifies. The female gathers bedding material, rearranges it, and constructs a compact nest. She spends extended periods in the nest, often remaining motionless for hours at a time.
Activity levels change markedly. The rat becomes less active, spends most of her time in the nest, and shows reduced appetite. She may also display short, rhythmic abdominal contractions, known as “pseudopregnancy contractions,” which precede actual delivery.
To confirm that delivery is imminent, follow these steps:
- Monitor temperature twice daily; note any consistent decline.
- Inspect the ventral area for swelling of the mammary glands and nipple changes.
- Check for discharge by gently examining the perineal region.
- Observe nesting; ensure the rat has sufficient, clean bedding and a quiet, low‑light environment.
- Record behavior; reduced movement and increased time spent in the nest are strong predictors.
- Count days; most laboratory strains give birth between day 21 and 23 of gestation, so proximity to this window heightens the likelihood.
Providing a quiet, warm nest with ample soft material, minimizing disturbances, and keeping the cage clean will support a successful delivery. If any signs of distress appear—such as prolonged inactivity, severe bleeding, or failure to deliver within 24 hours after the temperature drop—consult a veterinarian promptly.