Why Do Dogs Have Nipples?Nipples are the external duct for the mammary glands. In female dogs, the mammary glands produce colostrum and milk to feed their young. Without nipples, a mother dog wouldn’t be able to feed her puppies and support life. In intact females, the nipples will actually swell during heat and pregnancy. They will eventually fill with milk during late pregnancy and throughout lactation.
What Do Dog Nipples Look Like?In spayed or neutered dogs, nipples will look and feel like little bumps, almost like pimples. They may be black, pink, or a combination of both colors. Some nipples may be more elongated, depending on the dog breed. In a dog that has had puppies or that isn’t spayed, nipples are generally bigger, and more stretched out.
Do Male Dogs Have Nipples?Male dogs do have nipples, just like females. Even though they don’t produce milk, nipples are a residual product of a developing fetus. Even though an embryo is genetically male or female, they follow the same developmental pathway for a short time. Nipples are formed on male and female embryos before the genitals are formed. In females, further development of mammary glands occurs, while in males, the development usually doesn’t go far enough to where they can produce milk.
How Many Nipples Do Dogs Have?The number of nipples that a dog has will vary depending on size and breed. This number usually falls between 6 and 10. Most of the time, dog nipples will be located starting in the groin area and extending in two rows along the belly and up to the chest. Nipples are symmetrical, meaning there is an even number on each side. However, it’s not uncommon for a dog to have an odd number of nipples. The number of nipples has to do with average litter sizes. The higher number of puppies that a breed has, the more nipples they will need to feed them. That’s part of the reason larger dogs have more nipples than smaller dogs-they tend to have larger litters. There’s also the issue of space; smaller dogs just don’t always have room on their belly to fit 10 nipples. The number of dog nipples is determined by breed, not gender. For example, male and female Golden Retrievers will have a similar number of nipples, while male and female Chihuahuas will also be similar. Males don’t tend to have fewer nipples than their female counterparts of the same breed. Instead, the number of nipples a dog has depends on its size.
What Problems Can Arise From Dog Nipples?Nowadays, most dogs are spayed or neutered, making nipples a useless feature on their body. Without going through a pregnancy or heat cycle, most female dog nipples don’t go through any changes in their lifetime. However, if your female dog isn’t spayed or was spayed after having puppies, there are a few conditions affecting the nipples and accompanying mammary glands.
- Mammary cancer: Mammary cancer is the canine equivalent to breast cancer in humans. It’s actually fairly common in older, intact females, but it can also occur in spayed females and male dogs. Mammary cancer often shows up as lumps under and around the nipple. There may also be swelling of the nipple or discharge. If your puppy has any lumps or bumps associated with a nipple, see your veterinarian as soon as possible.
- Mastitis: Mastitis is inflammation of the mammary gland. It most often occurs in lactating mothers following a bite or injury to the nipple, allowing bacteria in. However, male dogs and non-lactating females can also get mastitis if bacteria get into the mammary gland and cause an infection. Mastitis will usually present as a red, hot, swollen nipple and mammary gland. The discharge or milk may be bloody, and the gland may be firm. The pup is usually pretty painful and may have a fever, lethargy, and a decreased appetite. If left untreated, mastitis can become systemic and severe.
- Skin cancer: The lightly haired regions of a dog’s belly can be more prone to certain types of skin cancer, mainly squamous cell carcinoma and melanoma. While these cancers aren’t particularly associated with a dog’s nipple, sun exposure on the lighter-haired areas around the nipple can be a contributing factor. Skin cancers can show up as dark, irregular-shaped spots or lumpy bumps. Most of the time, they grow fairly quickly. If your pup shows up with any new lumps or bumps, have them checked out by a veterinarian.
- Dermatitis: Dermatitis means inflammation of the skin. It can happen for all kinds of reasons, most commonly due to allergies or something that they came in contact with. Dermatitis isn’t caused by or made worse by a dog nipple; rather, you may notice it around a nipple before noticing it elsewhere. This is because the skin around dog nipples has less hair, making contact with allergens easier and making it more noticeable to you. Dermatitis often shows up as a red, scabby rash. Pups are often itchy and will lick or scratch the area. Further examination may show small bumps or weeping. A skin infection may be the next to come if the dermatitis isn’t treated.
Conclusion for Everything You Need to Know About Dog NipplesWhether this is the first time you’ve noticed or given thought to your dog’s nipples, they’re not something to be forgotten. Understanding what’s normal with dog nipples can help you to catch something problematic before it becomes a huge problem. When it comes to dog nipples, make sure to have any lumps, bumps, or discolorations checked by a veterinarian. Other articles you might like:
- My Dog Has to Sleep Touching Me
- Why Does My Dog Stretch So Much?
- What Can I Give My Dog To Sleep At Night?
Other Frequently Asked Questions
How many nipples do male dogs have?The number of nipples a male dog has depends on the size of the dog breed. Large male dogs will have more nipples than smaller male dogs. Generally speaking, the number of nipples a male dog has ranges from 6 to 10. It’s not uncommon for a boy dog to have an odd amount of nipples.
What causes a female dog’s nipples to turn black?There are many reasons that a female dog’s nipples can turn black. Hormones can cause discolored nipples in non-spayed female dogs. If your dog is pregnant, its nipples can enlarge and turn a red color. Additionally, you’ll want to check your female dog for mammary cancer or mastitis. If you feel bumps and their nipples turn a dark black color, you will want to see a veterinarian immediately.
Do dog nipples shrink after spaying?Yes, dog nipples will shrink after spaying if your female dog was experiencing hormonal changes. However, their nipple size after spaying highly depends on if they were in at the time heat, their age, and how many prior heat cycles they had. During a heat cycle, your female dog’s nipples will typically enlarge due to the mammary gland and mammary tissue changes. After spaying, your girl dog no longer will have heat cycles, so their nipples usually shrink.
Do a dog’s nipples get bigger when in heat?Yes, a female dog’s nipples generally enlarge during and after its heat cycle as a way to prepare for a possible pregnancy. Their nipples enlarge from the changes in the mammary gland and mammary tissue. This is also known as false pregnancy or phantom pregnancy when a female shows signs of being pregnant. After a couple of weeks, their nipples tend to shrink back down to normal size.
When I squeeze my dog’s nipples liquid comes out. What should I do?Liquid discharge is common if your female dog is pregnant. However, if your girl dog is not pregnant, then they should not be lactating. If liquid is coming out of your dog’s nipples and they are not pregnant, this is likely a sign of infection in the mammary gland. You should see a veterinarian immediately to check for mammary cancer.
Why does my dog have 9 nipples?Most of the time, a dog has an even number of nipples that are symmetrical. However, it’s not uncommon for a dog to have 9 nipples or an odd number of nipples. Some people will look at it as an extra nipple or a missing nipple. The fact is there is no right or wrong number of nipples. Nipple development occurs early on in the embryo cycle, even before their genitals are formed.
Why doesn’t my female dog have nipples?All female dogs have nipples that are formed during their developmental cycles as embryos, but they may be difficult to find. If your female dog is spayed, oftentimes, their nipples are flat or sometimes slightly inverted, making them difficult to locate. This is especially true if you have a dog with hair on its belly. While you might think that your female dog doesn’t have nipples, they most certainly do.
Do dog nipples shrink after having puppies?Typically, your dog’s nipples will shrink back to their normal size after their mammary glands produce colostrum and milk which they use to feed their puppies. The transition period when her puppies no longer need milk and are weaning toward solid food is when a dog’s nipples will shrink. However, not all dog’s nipples will shrink after they have puppies.
Dr. Sabrina Kong graduated from the Royal Veterinary College in England in 2016 and has been working at a small animal clinic in Northern California since then. She grew up in the Bay Area and got her bachelor’s degree from Cal Poly San Luis Obispo. She also became a Certified Canine Rehabilitation Practitioner through a program at the University of Tennessee.
When she isn’t in the clinic taking care of her four-legged patients, she enjoys traveling and trying new foods with her friends and her three-legged dog, Apollo. She adopted Apollo from her clinic when he was a puppy with numerous health issues. Dr. Kong truly cares about taking care of animals.