How can you determine the sex of a dwarf rat? - briefly
Examine the anogenital region: males have a visible testicular bulge and a larger, more pronounced distance between the anus and genital papilla, while females show a smooth, shorter space with a simple genital opening. Use a magnifying lens if needed to confirm these differences.
How can you determine the sex of a dwarf rat? - in detail
Identifying the gender of a miniature rat requires careful visual examination of the genital area, often aided by gentle handling and adequate lighting.
First, secure the animal by holding it in a cupped hand, supporting the body with the thumb and forefinger while the remaining fingers stabilize the hindquarters. Use a soft, non‑abrasive surface to prevent stress. Position a bright lamp or magnifying lamp at a comfortable distance to reveal fine anatomical details.
The key structures differ between males and females:
- Males: A single, elongated organ (the penis) is visible just below the tail, accompanied by a pair of small, oval testes that may be partially concealed by fur. The distance between the anus and the genital opening (the anogenital distance) is relatively long, often exceeding 5 mm in adult dwarf rats.
- Females: Two parallel openings are present—the vaginal orifice and the anal opening—separated by a short distance, typically less than 3 mm. No protruding organ is observed, and the area appears smoother.
When the animal is very young or its fur is dense, gently part the hair with a soft brush or a fine cotton swab. If the sex remains ambiguous, compare the anogenital distance with reference measurements for the specific strain and age; male dwarf rats consistently exhibit a greater separation.
For confirmation, a veterinarian may perform a brief ultrasound or, if necessary, a genetic test using a cheek swab. However, the visual method described above provides reliable results for most breeding and research purposes.