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Why Do Male Dogs Have Nipples? Vet-Approved Anatomy Facts

Beth Crane

By Beth Crane

Xoloitzcuintle - hairless mexican dog

Vet approved

Dr. Chyrle Bonk Photo

Reviewed & Fact-Checked By

Dr. Chyrle Bonk

DVM (Veterinarian)

The information is current and up-to-date in accordance with the latest veterinarian research.

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Image Credit: Seregraff, Shutterstock

You might be concerned if you’re stroking your male dog’s belly and feel several small bumps. If your dog has little raised bumps in two lines going down their abdomen, it’s likely their nipples! Male dogs (like male humans) have nipples, and there’s an interesting reason for it.

Both male and female embryos develop in the same way until sexual differentiation occurs. During this time, both develop nipples. After sexual differentiation, those nipples go on to further develop in order to be able to provide nourishment for their young in females. In males development stops, creating what’s known as a vestigial structure. Since nipples don’t necessarily cause any harm in males, evolution determined not to select against them and remove them.

Male dogs have the same number of nipples as females: around 10 (five on each side). Some breeds have more or fewer, but they’re usually in two equal lines running down the abdomen. While it’s normal for your male dog to have nipples, there are still a few things you should look out for and possibly other reasons why your dog has bumps on their belly.

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Frequently Asked Questions (FAQ)

So, you’ve learned why your male dog has nipples and what caused them to be there, but what about problems they may have with them? Read on to find the answers to common anatomy questions and other facts.

Can Male Dogs Have Problems With Their Nipples?

Male dogs can have problems with their nipples, but they are less common than in female dogs. Lumps in or around their nipples are most common in intact females, but they can rarely occur in males as well.

Finding a mass or lump around your dog’s nipple could signify a problem that your vet should check out. These lumps can be tumors or infections. Infections can be caused by trauma (such as scratches), skin problems in the area, and poor hygiene. Both can cause your dog to scratch or bite at their nipples and make them sore. Signs of a tumor or infection in the nipples include the following:

  • Redness
  • Swelling
  • Discharge
  • Pain or discomfort
  • Bleeding

Male dogs can also rarely experience swelling of the mammary glands due to hormonal imbalances, ingestion of certain toxins, or tumors in other areas (such as the testicles).

If you think your dog has health problems relating to their nipples, you should take them in to see your veterinarian promptly. Removal of the nipples in dogs is sometimes recommended if they cause problems, especially in cases of cancer.

Is This a Nipple or A Tick?

tick on the dog
Image Credit: chanon khunkitti,Shutterstock

It can be challenging to distinguish between a nipple and a tick on a dog because they feel very similar! Both are small and slightly firm to the touch, but it’s important to distinguish between them before you try to remove them!

Nipples on male dogs are usually smaller than those on females and can be either a pinkish or brown color, depending on your dog’s skin color underneath. However, the easiest way to distinguish a tick from a nipple is to look for legs.

Nipples don’t have legs; while an engorged tick can look and feel very similar to a nipple, looking for the presence of legs can help you identify which is which. Ticks have eight legs, which may or may not be gently moving. Ticks are often firmly attached to your dog’s skin, whereas nipples will blend into the surrounding skin. As always, if in doubt, ask your vet.

Other Bumps Similar to Nipples

Skin tags are overgrowths of tissue, usually on areas that rub together. They’re harmless and can be found on places like your dog’s chest, abdomen, and neck. Skin tags are more common in dogs that are elderly or overweight, and they’re soft with a thinner connection at the bottom of the skin-colored growth.

Lipomas (small fatty growths) and other benign (non-dangerous) tumors can also sometimes be mistaken for nipples if they’re small. It’s essential to monitor your dog’s nipples and skin for any changes and take them to the vet for a check-up if anything is concerning.

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Final Thoughts

Male dogs have nipples like female dogs, with the main difference being the size (and of course, function). They have the same number as females, and they’re evenly spaced in two lines going down the abdomen. Male dogs don’t have a use for their nipples like female dogs do, but since they are part of normal embryonic development prior to sexual differentiation, they’re born with them anyway.

There’s no advantage or disadvantage for males to have nipples, and they’re just left over from the early stage of development. The important thing to know about your male dog’s nipples is what normal is so that you can more quickly identify anything abnormal about their nipples and see a vet if something changes.

Featured Image Credit: Seregraff, Shutterstock

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