Cats usually have six to eight nipples, arranged in two rows along the belly. Six and eight are both common, and an odd number or an asymmetric arrangement happens and is not a problem.

Do male cats have nipples

Yes. Male cats have nipples just as male humans do. Nipples form early in development, before the sex specific hormones take over, so both sexes end up with them.

In males they stay small and non functional. They are simply harder to find under the coat, which is why owners are often surprised.

Nipples do not tell you the sex

A common belief is that only females have visible nipples. They do not. Sex is determined by looking at the distance between the anus and the genital opening and at the shape of that opening, not by counting nipples.

What is normal

Small, pale pink, flat and soft, evenly spaced in two rows. In cats with dark coats the skin around them may be pigmented.

In an unspayed female, the nipples enlarge and become pinker in pregnancy, usually noticeable from about the third week. They enlarge again with lactation.

What is not normal

This is the part worth knowing.

A firm lump under or beside a nipple. Mammary tumours are common in unspayed female cats, and in cats a high proportion of them are malignant. Any lump in the mammary chain should be examined promptly, not watched.

Redness, heat and pain, particularly in a nursing queen, suggests mastitis, an infection of the mammary gland. It needs treating.

Swelling of several glands in a cat that is not pregnant can be fibroadenomatous hyperplasia, a hormonal condition seen in young unspayed females and in cats given certain hormonal drugs.

Discharge from a nipple in a cat that is not nursing.

Neutering and mammary tumours

Spaying substantially reduces the risk of mammary tumours in cats, and the effect is strongest when it is done early. This is one of the most concrete health arguments for neutering, alongside preventing pyometra and unwanted litters.

What to do

Run your hands along the belly occasionally when your cat is relaxed, feeling both rows. It takes seconds and it is how most mammary lumps are found early.

If you find a lump of any size in an adult cat, book an examination. In cats, waiting to see whether it grows is not a good strategy.