TABLE 6-5.

Determination of the Sex of Mature and Immature Rodents and Rabbits

Mature hamsters, mice, rats, guinea pigs, and gerbils
Male	Female
1.Anogenital distance longer in the male 2.Manipulate “genital papilla”(prepuce) to protrude penis. 3.Palpate for testicles either in a scrotal sac (if present) or subcutaneous in inguinal region. 4. Males have only two external openings in the inguinal area: a. Anus b. Urethral orifice at tip of penis. In very fat males there may be a depression between the penis and anus. This depression can be obliterated by manipulating the skin in this area.	1.Anogenital distance shorter in the female. 2. Look for the three external openings in the inguinal area: a. Anus (most caudal opening). b. Vaginal orifice (middle opening) – look carefully. c. Urethral orifice at tip of urethral papilla (most anterior opening). In these animals the urethral papilla is located outside the vagina (unlike dogs and cats). In very fat females or young females, the vaginal orifice may be either hidden by folds of skin (the former) or sealed (latter). Gentle manipulation of the skin in this area will divulge the orifice.
Mature rabbits
Male	Female
1.Protrude penis by manipulating skin of prepuce. 2.Palpate for testicles. 3.Anogenital distance is longer.	1.There is a common orifice for both the vagina and urethra (like dogs and cats). 2.No. structure like a “penis” can be protruded from the urogenital orifice. 3.Anogenital distance is shorter

From Schuchman SM: Individual care and treatment of rabbits, mice, rats, guinea pigs, hamsters, and gerbils. In Kirk RW, ed: Current Veterinary Therapy X. Philadelphia, WB Saunders, 1989, p 740.