Post actualizado el día octubre 25, 2026 by DeiviSanzPlay
Have you ever found yourself staring at a newborn kitten, not knowing whether it’s a boy or a girl? Don’t worry, you’re not the only one. At first glance, and even more so if they’re kittens just a few weeks old, things get complicated. But there are tricks that always work. Here I’ll tell you how to distinguish a cat’s sex without getting confused, with details I’ve verified in practice.
The distance between the anus and the genitals: the infallible method
If you want to know whether a cat is female or male, the first thing you need to look at is the separation between the anus and the genital area. It’s the most reliable indicator, even in kittens just days old.
In males, that distance is greater: there’s a considerable space between the anus and the penis. You’ll also see a small rounded bump below the anus, which is the prepuce. In females, the distance is minimal, almost touching, and the opening has the shape of a vertical slit, like a little line.
You can try this with a kitten just a few weeks old. Males still have their testicles inside the abdomen, but the distance is already noticeable. It’s the first check any veterinarian does.
Visible testicles: only in unneutered males
As the cat grows, especially from 5 or 6 months onward, the testicles descend and become visible. If he isn’t neutered, you’ll see two little round bumps below the anus, separated by a small distance. In some cats, especially long-haired ones, they’re harder to see, but you can feel them by touch.
Females don’t have testicles, obviously. The genital area is flat, with a vulva that looks like a slit. If the cat is already neutered, the testicles are gone, but the anogenital distance is still greater than in a female and the prepuce is still there.
Watch out: don’t confuse the testicles with the anal glands. The latter are on the sides of the anus, not below it. If you see two bumps right below the anus, they’re testicles.
Behavior also gives clues (but it isn’t definitive)
Unneutered males tend to be more territorial. They mark with urine in a vertical position, especially if there are females in heat nearby. They can also be more dominant with other cats. Females, on the other hand, when they come into heat, become more vocal, rub against everything, and adopt a courtship posture with their tail raised and their hind legs treading.
But be careful: there are neutered males that are incredibly calm and females that are truly dominant. Behavior isn’t scientific proof. Use it as a complement, never as your only source.
Size and build: real differences
Male cats tend to be larger and have sturdier bones than females. Their heads are also broader, and their bodies more muscular. But this isn’t universal: there are large females and small males, especially in breeds like the Siamese or the Abyssinian.
If the cat is young, don’t rely on size. Wait until it’s a year old to compare. In any case, if you have doubts, the anogenital distance is still the best indicator.
Veterinary examination: the safe option
If you can’t figure it out, a veterinarian can determine it in seconds. With a gentle palpation or simply by observing the area, they’ll tell you whether it’s male or female with no margin for error. You don’t need to spend much; a routine checkup will confirm it for you.
Also, if the cat is going to be sterilized, the veterinarian themselves will tell you the sex before surgery. But don’t wait for that if you’re in a hurry to know.
Common mistakes when trying to determine a cat’s sex
The most typical mistake is confusing the male’s prepuce with the female’s vulva in very young kittens. The key is in the shape: in the male, the two dots (anus and prepuce) form a kind of separated pair of dots, like two circles. In the female, the anus and vulva are so close together that they look like a lowercase letter «i» or an inverted exclamation mark.
Another mistake is going by color alone. There are no colors exclusive to males or females, except in specific breeds like the tortoiseshell cat, where almost all are female for genetic reasons. But that’s the exception.
Quick summary to clear up any doubts
- Male: greater anogenital distance, rounded prepuce, visible testicles if not neutered, larger size.
- Female: short distance, slit-shaped vulva, no testicles, smaller build.
- Behavior: males mark more; females in heat meow and rub against things.
- Veterinarian: the definitive confirmation.
With these tricks, you won’t have to wonder anymore whether your cat is female or male. And if you’re still unsure, you can always take a look at the area in good light and with a little patience. Nature doesn’t deceive.
