Sexing Kittens - tips and hints to determine the sex of your kitten or cat.

Veterinary Advice Online - Sexing Kittens and Cats.

A lovely litter of 3-week-old kittens: four boys and one girl. Many cat owners find it very difficult to determine the sex of kittens, particularly newborn kittens, and often need their veterinarian to sex their kittens for them.

Now you can determine the sex of your kittens all by yourself!

This page contains everything you, the pet owner, need to know about sexing kittens and cats. Information provided on this page is supported by a number of helpful pictures and photographs that clearly illustrate how to distinguish the boys from the girls. Topics are covered in the following order:

1. Some basic dos and do nots when handling and sexing kittens for the first time.

2. How to tell male kittens from female kittens.

1. Some basic dos and do nots when handling and sexing kittens for the first time.

There is not too much that can go wrong when attempting to determine the sex of kittens, however, I will draw your attention to a couple of important kitten-handling dos and do nots, which should be taken into consideration.

DO:

Handle your kittens gently.
Rest your kittens on a clean towel on their bellies and lift their tails gently to examine their genitals.
Where possible, wait to sex kittens until they are over 3-4 weeks of age.
Make sure that your cat (the mother cat) is comfortable with you handling her kittens before proceeding to touch them.
Put kittens back with their mother immediately if they become distressed from handling.
Handle young kittens in a warm area and for no more than 5-10 minutes at a time so that they do not get cold.

DO NOT:

Handle kittens roughly.
Pick kittens up by their tails or hang them by their tails (they are not mice!)
Let kittens spin or twist around on their tails while you are holding their tails (this can result in tail fractures).
Handle newborn kittens (kittens under 3 weeks of age) if you can avoid it. Mother cats (especially new mothers) can become uncertain of their new kittens if you handle them too much and get your human smell all over them. This can potentially lead to the mother cat rejecting her kittens.
Handle kittens if they are still suckling (not yet weaned) and their mother is clearly distressed by you handling them.
Handle newborn kittens (<3 weeks old) for long periods of time. They can become cold away from the nest.
Attempt to expose or pull out the penis of prepubescent male cats (cats under 6 months of age). Such animals are not capable of exposing their penis and attempting to do so forcibly can damage the penis.

2. How to distinguish male kittens from female kittens.

The best way to determine the sex of male and female kittens is to rest the kittens on their bellies on a warm (not hot) towel, gently lift their tails and examine their genitals. There are several differences that exist between male and female kittens, even newborn kittens, which you can look out for when sexing kittens.

1. Examine the distance between the kitten's anus and genitals (vulva in females and penis in males).

Look at the pictures below. These are close-up photographs of the anuses and genitalia of two individual 3-week-old kittens. The first kitten (kitten on the left) is a young male and the kitten beside it (on the right) is a young female.

Genitals and anus of 3-week-old male kitten.

What you will notice from these two images is that the distance between the anus and the penis of the young male kitten (image 1) is a significantly greater distance than the distance between the anus and vulva of the young female kitten (image 2). I have labeled the images below (the same images as those above) to more clearly illustrate these differences for you.

Male kitten sexing - image of male kitten genitalia. Female kitten sexing - image of female cat genitalia.

2. Examine the shape of the kitten's genital opening (vulva or penis).

Look at the pictures below. These are close-up photos of the genitalia of two individual 3-week-old kittens. The first kitten is a young male and the kitten beside it is a young female.

Sexing kittens - male kitten genitalia. Sexing the common house cat - female kitten genitalia.

What you will notice from these two images is that the genital opening (penis or penis-sheath opening) of the young male kitten (image 1) is shaped like a small circular dot, whereas the genital opening (vulva) of the young female kitten (image 2) is shaped like a vertical slit. I have labeled the images below (the same images as those above) to more clearly illustrate these differences for you.

Sexing kittens - male kitten genitalia is shaped like a dot. Sexing the common house cat - female kitten genitalia is shaped like a slit or dash.

3. A bulging scrotal sac should start to become visible in male cats from about 10-12 weeks of age.

The scrotal sac or scrotum is a bulging out-pouching of skin that contains the testicles of male cats. It is located between the anus and penis of male kittens and cats. In a newborn male kitten, the testicles are tiny and the scrotal sac barely recognisable (e.g. you can not see the scrotal sac in the pictures of the 3-week-old male kittens above), however, as the kitten gets older (10 weeks +) and its testicles start to enlarge, the scrotal sac starts to protrude outwards and become very obvious. If you can see a clearly-defined scrotal sac, the kitten or cat is a male.

Sexing kittens - The scrotal sac is not clearly visible in this 3-week-old male kitten because its testicles are very small and its scrotum not yet fully developed.
Image: The scrotal sac is not clearly visible in this 3-week-old male kitten because its testicles are very small and its scrotum not yet fully developed.

Sexing kittens - the small, but obvious, bulge between this kitten's anus and penis is its scrotum. This kitten is a boy.
Image: This is an image of a 12-week-old kitten who is currently anesthetized prior to being neutered. To orientate you - the kitten is lying on its back. You can already see a small, but obvious, bulge between this kitten's anus and penis. This is the scrotum with testicles inside. This kitten is therefore a male.

Male kitten sexing - The scrotum (the bit resting upon the pink surgical swabs) is well-developed and very obvious with two individual bumps inside it: the two testicles.
Image: This is a picture of an 8-month-old male cat who is currently anesthetised prior to being neutered. To orientate you - the tomcat is lying on its back. The scrotum (the bit resting upon the pink surgical swabs) is well-developed and very obvious with two side-by-side, individual bumps inside it: the two testicles. The penis too is well-developed and somewhat pendulous. If you see a cat with these genital features, it is definitely a boy.

Author's note: Kittens or cats with retained or undescended testicles (cryptorchid cats) will not develop an obviously enlarged or pendulous scrotum.

4. Testicles should be palpable in the male scrotum from the time of birth.

The testicles of male kittens descend into the scrotal sac just prior to the kitten being born. It is therefore possible for testicles to be palpated in the scrotal sac regions of very young male kittens, even if the scrotum sac itself has not yet obviously enlarged. For example, testes were clearly palpatable in the scrotal region of the three-week-old male kitten pictured above, even though no scrotum could be seen.

To feel for testicles: gently but firmly place your fore-finger and thumb either side of the kitten's scrotum (or, in a very young kitten, where the scrotum should be) and slowly and gently bring your fingers together in a pincer-action, sliding your finger-tips firmly along the skin of the kitten's scrotum. If the kitten is a male, what you should feel between your fingers are two smooth, ovoid, small (approx 3-5mm diameter in a 3-week old kitten) objects located side-by-side underneath the skin of the scrotal sac region. These are the testicles. Often you'll only feel these testicles one at a time (it is hard to grab both at once in a small male kitten) and often these testes will deftly slide away from your finger-tips when pressed (they are tricky to grasp hold of and feel like small peas rolling away under your fingers).

Male kitten sexing - This photo shows where to palpate for testicles in a male kitten or cat.
Image: This pic shows where to palpate for testicles in a male kitten or cat.

Author's note: You may not be able to feel the testicles of kittens or cats with retained or undescended testicles (cryptorchid cats) because their testicles will be located ahead of the scrotum, perhaps even within the cat's abdomen.

5. Colour can be your guide.

Occasionally, the fur color of your cat or kitten can give you some indication as to the sex of the kitten.

Tortoiseshell cats (cats with three colours - white, black and orange) are almost always female.

Ginger cats are predominantly male, but can sometimes be female. Ginger is a less-reliable colour indicator of feline sex.

Tortoiseshell cats (torties) are always female except in a few rare instances.

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Copyright November 9, 2008, Dr. O'Meara BVSc (Hon), www.pet-informed-veterinary-advice-online.com.
All rights reserved, protected under Australian copyright. No images or graphics on this Pet Informed website may be used without written permission of their owner, Dr. O'Meara.