Cat nipples: Everything you need to know

Like humans, cats are mammals. As such, they breastfeed their young, and they have nipples which are attached to the mammary glands. Also, like humans, both male and female cats have nipples. They run in two rows along the abdomen above the pelvis and below the chest. Cat nipples are small and can be easy to miss, especially if the cat has long fur.

How many nipples do cats have?

Interestingly, not all cats have the same number of nipples. While humans nearly always have two nipples, cats can have anywhere between four to ten nipples, with most felines having eight nipples. A few cats have an odd number of teats.

Breed, age, and sex don’t affect how many nipples a cat has. You could have a female cat with four nipples and a male cat with eight. Even kittens from the same litter can have different numbers of nipples.

And yes male cats have nipples too. Check out our in-depth article about how to determine a cat’s gender.

Where do a cat’s nipples come from?

A cat’s sex is determined by their chromosomes. While humans have 23 pairs of chromosomes, cats have 19 pairs, including a set of sex chromosomes, X and Y. Every kitten inherits a sex chromosome from each parent. Girl kittens will have XX chromosomes, while their brothers will have XY chromosomes. Since cats can only inherit a Y chromosome from their father, it’s the father’s chromosomes that determine what sex a kitten will be.

In cats and many other placental and marsupial mammals, the Y chromosome has a gene called SRY, whose job is to start the process of masculinization or virilization. It does so by stimulating the production of male hormones like testosterone that cause the kitten to develop male genitalia. The male hormones also cause the kitten’s mammary glands to stop growing. The development of cat nipples is believed to take place fairly early during a cat’s pregnancy as they are already present by the time the sex hormones start signaling whether the kitten is male or female.

While most male cat nipples don’t lactate or produce milk, there are rare cases of male cats lactating. Lactation in a male cat can be caused by exposure to drugs containing hormones or by stimulation of the nipples through frequent massages of that area.

Can you tell a cat’s gender by its nipples?

Generally speaking, no. Nipples on female and male cats look the same. In order to sex a cat, you need to look at its rear and check the shape of the genital opening and its distance from the anus, the usually pinkish orifice above it. In a male cat, the genital opening will be round and at least ½ inch from the anus; in a female, the genital opening will be shaped like a line and close to the anus.

A cat’s coat color can also indicate its sex. Calicos and tortoiseshells are nearly always girls, while orange tabbies are more likely to be boys. One of the genes determining coat color is found on the X chromosome. Cats need two copies of the gene to become tortoiseshells or calicos and thus require two X chromosomes, which means they need to be female. Male cats with the gene will be black or orange depending on which allele or version of the gene they have.

The only time you can tell a cat’s gender by looking at the nipples is if you are looking at a pregnant female. As with humans, a cat’s nipples change during pregnancy. During the third week of pregnancy, a cat’s nipples will start to swell and turn pink. They may also become darker as the pregnancy progresses.

Other signs of pregnancy can include the following:

  • Weight gain and increased appetite
  • Rounder and bigger abdomen
  • Unusually affectionate behavior

You should also suspect pregnancy if your cat went into heat, and you have seen male cats in the area.

Pregnancy in cats can last anywhere from 58 to 70 days, with 64 days being the average. A typical litter will have between four and six kittens.

How should you care for a pregnant cat?

The first step is to determine if she is pregnant. Unfortunately, there are conditions besides pregnancy that can cause a cat’s nipples to become enlarged. A veterinarian can determine if a cat is truly pregnant. They will probably use ultrasound to confirm the pregnancy.

Cats usually mate between September and March, so the timing of an apparent pregnancy can be a clue as to whether the cat is really pregnant.

Cats will need an extra-nutritious diet while they are pregnant, and while they are nursing their kittens. You should thus start feeding your cat wet kitten food at the midpoint of her pregnancy or around the fifth week. Royal Canin, for example, makes a wet kitten food that they describe as being for “mother and baby cat.”

Just as a pregnant woman’s appetite increases since she is “eating for two,” a pregnant cat’s appetite will also increase, possibly by as much as 50 percent. Since the developing kittens will put pressure on the mother cat’s abdomen, she will need to eat many small meals rather than the two large meals cats normally eat.

Some authorities recommend giving a pregnant cat extra protein in addition to the kitten food. This can take the form of small pieces of chicken, egg, fish, or beef. Mix it in with the cat’s food. Continue giving the cat extra protein until her kittens are weaned.

After the cat has given birth, feed her kitten food and extra protein three times a day. Also, give her something with a lot of calcium to help milk production. The veterinarian may recommend a cat food high in calcium, or they may recommend calcium supplements.

Are leaking nipples normal?

Nipples that are leaking milk are fairly common in a pregnant cat, especially if she is about to give birth. Lactation in a pregnant cat is actually a good sign, for it means that the mother cat will have plenty of milk for her kittens.

Lactation or milk production can also occur in spayed cats but is far rarer. Some cats can develop a condition called “false pregnancy” and should be seen by a veterinarian, especially if the false pregnancy lasts longer than a few days.

What is agalactia?

Agalactia is a condition in which a mother cat stops producing milk prematurely. Under normal conditions, a mother cat will stop producing milk a few days or weeks after her kittens are weaned. Agalactia, however, often develops right after the kittens are born.

As a healthy mother cat usually has no trouble nursing her young, a failure to produce milk indicates a health problem that can range from a bacterial infection to cancer.

If a cat seems to have trouble feeding their kittens, it’s imperative to take the entire family to the vet. Not only does the mother need to be examined, but the kittens will need kitten formula to keep them from dehydrating. The veterinarian can provide guidance on both the best formula and how to feed the kittens.

What is a false pregnancy?

False pregnancy or pseudopregnancy is a condition in which a cat ovulated but did not conceive. As the name suggests, the cat shows signs of pregnancy like enlarged nipples and milk production. She may also show some of the behavioral changes seen in pregnant cats.

The veterinarian will examine the cat to determine if she is truly pregnant. False pregnancy usually goes away on its own within one to three weeks, so the cat usually does not need treatment. In fact, treatment may make the condition worse. For example, trying to milk the cat by massaging her nipples will only stimulate the production of more milk.

False pregnancy is less common in cats than it is in dogs. It is most likely to develop about a month or two after a cat’s last heat, and it is usually caused by a hormonal imbalance. Spaying a cat will reduce the likelihood of her developing a false pregnancy, and the vet may also recommend supplemental hormones.

Can cats get breast cancer?

Unfortunately, yes. Veterinarians call it “mammary cancer,” and it describes tumors that develop within the nipples.

Tumors in the mammary gland start off as small lumps. About 85 percent of such tumors are malignant or cancerous, and malignant tumors tend to grow and spread or metastasize quickly. Mammary cancer usually affects more than one nipple.

A cat with mammary cancer will tend to groom and lick the affected nipples to an excessive degree. The nipples will become infected and even necrotic and thus produce a strong odor. As cancer progresses, the cat will show signs of overall poor health like depression or anorexia.

Getting a cat spayed before she reaches the age of six months will reduce her risk of developing mammary cancer.

Are there other diseases that affect the nipples?

Yes, there are. Examples include the following:

  • Feline Mammary Hypertrophy
  • Mastitis
  • Galactostasis
  • Mammary Hyperplasia

In feline mammary hypertrophy, the cat develops benign masses in at least one of its nipples. The condition is caused by the hormone progesterone. Spaying is the most common treatment for feline mammary hypertrophy and prevents it from recurring.

Mastitis is an inflammation of the mammary glands that often develops after a cat has given birth. It is usually caused by a bacterial infection and can involve one mammary gland or several glands. A non-bacterial form of mastitis can develop in a mother cat whose kittens have just been weaned. In both types of mastitis, the affected mammary glands will be swollen, hot, and painful. If bacterial mastitis becomes generalized, the cat may show other signs of illness like lethargy, fever, and poor appetite. She may also stop taking care of her kittens. In non-bacterial mastitis, the mother cat will seem normal and alert. Both types of mastitis can be treated by applying warm compresses to the affected glands four to six times every day. The veterinarian will prescribe antibiotics for bacterial mastitis.

Galacatostasis is another condition that affects mother cats that have weaned their kittens or cats with pseudopregnancy. In both cases, the cat has an abnormally high accumulation of milk that causes inflammation.

Mammary hyperplasia or mammary gland hyperplasia is a benign condition in which the cat’s mammary glands become enlarged due to an excessive amount of tissue. It is most commonly seen in young female cats that have not been spayed, but it can affect cats of either gender even after being fixed. It can also occur in cats that are being given progestogen medication.

A cat with mammary hyperplasia will develop one or more enlarged mammary glands. They will feel firm, and they won’t cause the cat any pain.

While mammary hyperplasia is benign, it can resemble mammary cancer. Thus, a cat with enlarged mammary glands should always be checked out by a vet who can determine the cause of the swollen mammary glands.

Although hypertrophy and hyperplasia both result in enlarged mammary glands, they have different causes. Hypertrophy is a condition in which cells become abnormally large. In hyperplasia, the increased size of the mammary glands is caused by an abnormally high number of cells. The cells in hyperplasia are normal-sized, but there are too many of them.


Nipples are an important part of a female cat’s anatomy, for they enable her to feed her young. Various conditions can affect cat nipples and impair the mother’s ability to nurse her young. Many illnesses cause the nipples to become enlarged – which also happens when the cat becomes pregnant. Thus, if your cat’s nipples look swollen, you need to take her to a veterinarian, especially if you don’t believe she is pregnant.

If your cat has kittens, her health will affect how well she can care for them. It is thus vital that you keep your cat healthy and report any signs of illness to your vet. It is equally important that you follow the vet’s instructions in caring for your cat and her kittens.

Leave a Comment