How can you determine the sex of a Dumbo rat at three weeks? - briefly
Inspect the anogenital region: males display a longer anogenital distance and lack prominent nipples, while females have a shorter distance and visible nipples. Palpation of the testes can further confirm male sex at three weeks.
How can you determine the sex of a Dumbo rat at three weeks? - in detail
Determining the gender of a three‑week‑old Dumbo rat requires careful visual examination of the anogenital region and secondary sexual characteristics. The following steps outline a reliable procedure:
- Position the pup on a clean, well‑lit surface. Use a magnifying lens if available.
- Locate the genital opening. In males, the distance between the anus and the genital papilla (anogenital distance) is noticeably longer than in females.
- Observe the shape of the genital papilla. Males present a small, rounded protrusion that often resembles a tiny penis; females display a more recessed opening without a protrusion.
- Check for the presence of testes. At three weeks, testes may be descended into the scrotum and appear as paired, slightly bulging masses beneath the skin. In females, the area remains smooth.
- Examine the nipples. While both sexes have nipples, males may exhibit a slight swelling of the mammary buds, whereas females typically have more pronounced development. This feature alone is not definitive but can support the assessment.
If uncertainty persists, a gentle palpation of the abdomen can help confirm the presence of testes in males. In research settings, genetic sexing via PCR of tail‑snip DNA provides absolute confirmation, but visual inspection remains the standard field method for this age group.