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Determination of Sex of an Animal

Dr. Lila Miller, D.V.M., ASPCA Sr. Director Animal Sciences & Vet Advisor


Determination of the sex of an animal

Determining the sex of animals, in most cases, is a fairly simple task. Mistakes are made most commonly in male animals whose testicles have not yet descended into the scrotal sac or may be retained in the inguinal canal, and in very young kittens. (See addendum)

The vaginal opening in female felines is a slit that appears below the anus.

The scrotum and penis in male felines also appear below the anus.

If visual inspection is not sufficient, the lips of the vulva may be gently spread apart to verify the presence of a slit.

In very young kittens, the testicles may be so small they cannot be visualized. The scrotal sac should be palpated to detect the presence of testicles. Alternatively, the sheath of skin covering the penis, or prepuce, can be gently pulled back to expose the penis.

Cryptorchidism or monorchidism are terms that describe a situation in which one or both testicles have not descended into the scrotal sacs. The testicles may both be retained in the abdomen, or somewhere in the ingunial region (inside on the inner thigh), where they may be palpated under the skin.

Many animals are being spayed or neutered at an early ace, so the absence of testicles may be due to surgery and not from the conditions described above. In these cases, additional efforts should be made to check for a tattoo.

Male animals have nipples, so their presence cannot be used as a criterion for determining the sex of animal.

© 2000 ASPCA

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