Black Nipple on Dogs? 6 Most Likely Reasons

When my daughter noticed our English Springer Spaniel had a black nipple, I checked the area. Because our furbaby is spayed, I knew she wasn’t pregnant or nursing, so I narrowed down my considerations. 

There are various reasons for black nipples. In this article, we’ll discuss the normal appearance of nipples, possible causes for black discoloration, and when the change is a cause for concern. I’ll share what you can do if your furbaby has black nipples and when you should call your vet.

What is the typical appearance of dog nipples?

The appearance of your dog’s nipples will depend on her breed and skin color. They can range in color from pink to black and look like small, fleshy moles. Both males and females have nipples, but they can be more pronounced in females, particularly if they’re in heat, pregnant, or lactating. 

Pictured above: Notice the nipples of this Jack Russel female after spaying. The bumps are low, rounded bumps with a light-pink fleshy color that blends with the skin around them.

Pictured above: Nipples on a pregnant female dog. The appearance is light pink and fleshy, and the teats are more elongated to prepare for nursing.

Pictured above: Nipples on a lactating female dog. Notice how the teats are swollen and more prominent to allow puppies to latch on and nurse.

Dogs generally have 6-10 nipples on their abdomens. Most of the time, there’s an even number because they occur in pairs.

Most likely reasons for a black nipple on a dog

There are various reasons your dog’s nipple/s can be black. Some are benign while others point to health issues.

Hyperpigmentation

Hyperpigmentation, or darkening and thickening of the skin, can occur on the nipples of dogs.   The darker skin pigmentation comes from a release of melanin triggered by friction, allergies, hormonal changes, inflammation, or infection. Signs of hyperpigmentation include:

• Rough, thick skin 
• Brown-black patches of skin 
• Hair loss
• Odor
• Possible itching or pain
• Secondary bacterial/yeast infection
• Red edges around inflamed areas of skin

Some cases of hyperpigmentation are merely cosmetic and will not have signs of inflammation or infections such as red edges, hair loss, odor, or pain/itching. Most other cases will resolve once your veterinarian identifies and treats the underlying cause. Treatment may include medicated shampoos, topical steroid ointments, and antimicrobials. It may take several months for the skin to look normal again.

Trauma/injury

Canine nipples can become discolored and turn black with repeated irritation or injury. If trauma or scratching breaks the skin’s surface, your dog will be susceptible to secondary infection. Possible sources of trauma or injury include:

• Irritation from puppy claws and teeth during nursing
• Rubbing the stomach across a rug or carpet(abrasions)
• Excessive licking or scratching around the nipples
• Rough play with other dogs
• Reaction to contact allergies that cause inflammation and irritation

Trauma or injury to the nipples can cause the breast tissue and nipples to turn purple or black from bruising. With skin disruptions, you may also see blood, serous discharge, or scabbing.

If your dog shows evidence of nipple trauma, you can try warm compresses to reduce the inflammation and bruising. Keep the area clean and monitor your furbaby for signs of an infection. You can use gentle, medicated shampoos to soften and clean scabs. For nursing bitches, use a protective covering on affected nipples in between feedings to reduce irritation.

Discoloration from trauma should resolve as the injury heals. If your is painful or uncomfortable, or if the injury is not healing after a few days, contact your veterinarian. He can examine the nipple for underlying conditions. For injuries, he may prescribe anti-inflammatory drugs, pain medication, and antibiotics for secondary infections.

Hormonal changes

Unspayed females can show nipple discoloration due to hormonal changes. When a bitch goes into heat and is bred, the nipples swell and the center areolae darken in preparation for pregnancy and lactation. Some intact females will also display these symptoms as part of false pregnancy. Male nipples can also darken in response to hormonal fluctuations. With females, signs of hormonal changes may include:

• Enlarged nipples
• Darkening nipples and areolae as blood supply increases
• Leaking milk later in pregnancy or during lactation
• Swelling or enlarging mammary tissue

If your dog shows signs of pregnancy, consult with your veterinarian to increase her nutrition for gestation and lactation. The color and size of the nipples should return to normal after weaning her puppies.

Infection/mastitis

Infections of the nipples/mammary gland usually arise from bacteria. Most cases of mastitis occur in pregnant or lactating bitches when microorganisms enter the gland or teat through abraded or injured skin surfaces. Symptoms of an infection include:

• Darkened nipples
• Swollen teats and glands
• Inflamed and painful, red/purple gland
• The area is warm/hot to the touch
• Serous discharge
• Lethargy
• Fever
• Loss of appetite

At home, discourage puppies from nursing the infected glands and hand-milk your dog. However, she should visit the vet for oral antibiotics and pain medications. Most of the time, mastitis responds well to treatment and clears up in 2-3 weeks. Severe cases may need IV antibiotics or surgery to remove abscesses and necrotic tissue.

Cancer

Certain types of cancers that can affect the nipples and mammary glands may turn the tissue black. Tumors that cause discoloration include mammary gland tumors, melanomas, and squamous cell carcinomas. Signs of cancer include:

• Nipple discoloration
• Changes in nipple size or shape/swollen glands
• Bleeding skin lesions or nipple discharge
• Skin ulceration or crusty skin surface
• Lumps or bumps in the mammary tissue or on the nipples
• Lethargy
• Weight loss

Cancer requires veterinary care. For superficial skin cancers, the treatment is surgical removal. If the tumor is in the gland, treatment will depend on the type and stage of the cancer but may include surgical removal, radiation therapy, or chemotherapy. The prognosis varies depending on the type, location, and cancer’s stage.

Inverted nipple

Inverted or recessed nipples in dogs are fairly common. When the tissue around the nipple thickens, it can pull the teat inward. Signs of inverted nipples include:

• Swelling around the nipple
• Nipple discoloration
• Red or discolored skin around the nipple
• Pain and irritation/difficulty nursing if lactating
• Discharge

Inverted nipples should be examined by a veterinarian. While they may be benign, the condition can point to an underlying disease like cancer. Additionally, leaving the condition alone can predispose your dog to mastitis or abscesses.

Treatment for inverted nipples varies depending on the cause of the inversion. Antibiotics help to clear up infections while topical ointments or creams can be applied for trauma. Severe cases may require surgical correction. 

When is it ok to wait and see?

Unless the skin around your dog’s nipples has naturally dark pigmentation, black teats can be alarming. Sometimes, the discoloration comes from dirt. When you notice a sudden color change in your dog’s nipples, clean and inspect the area. If the dark coloration persists, check for signs of pain or swelling. 

 When nipple discoloration is caused by an injury, pregnancy, or nursing you may be able to monitor your dog at home and see if it improves. Notify your veterinarian about the condition and observe your pooch closely for signs of pain or infection.

When should you be concerned?

Nipple discoloration can have a variety of underlying causes, and some are concerning. Schedule an examination with your veterinarian if: 

• The discoloration doesn’t resolve or grow larger 
• Swollen nipples when your dog is not pregnant
• The nipple is leaking or oozing liquid
• The area has a bad odor
• Nipples have a crusty appearance
• Your dog is excessively licking or scratching at the area 
• Your dog has signs of infection like fever, lethargy, or loss of appetite

What you can do when your dog’s nipples turn black

When your dog’s nipples turn black: 

• Gently clean the area with a dog-safe cleanser to remove dirt and debris
• Observe the area for signs of pain, odor, or redness
• If your dog isn’t pregnant or nursing, look for signs of swelling
• If there was a recent injury, use warm compresses to reduce inflammation
• Protect injured teats by wrapping or covering them to prevent further trauma
• Contact your veterinarian and report your observations.

Would a vet be able to help over a video call?

In some cases, a video call with a vet provides a more affordable first step to rule out certain conditions. If your furbaby has a fresh injury or is pregnant/nursing, your veterinarian may be able to recommend a course of treatment over the call. With other conditions, the doctor will be able to ask you questions about your dog’s symptoms and history to help narrow down the list of possible diagnoses.

However, many conditions that cause nipple discoloration have common signs. Video calls will not allow your vet to run diagnostic tests or take samples of skin crusts or nipple discharges to reach a final diagnosis. If your pooch has a fever or unusual swelling of the nipples or mammary glands, you should schedule an office visit.

Frequently asked questions

Can a black nipple on my dog be a sign of cancer?

Black nipples on dogs can be a sign of certain cancers including melanoma and squamous cell carcinoma. If you notice signs of cancer listed in the “likely reasons” section above, contact your veterinarian.

My dog’s blackened nipple seems painful; should I be worried?

When nipples turn black and become painful, it can be a symptom of infection or injury. You should take your dog to the vet for an examination and treatment. Some conditions can get steadily more severe without appropriate care.

Can spaying or neutering my dog affect nipple color?

When female dogs are spayed before their first heat or male dogs are neutered before sexual maturity, the nipples usually shrink and look more like puppy nipples. However, when females are spayed later in life, the teats may not change in shape or color. 

If your dog’s nipples become discolored immediately following a spay or neuter surgery, it may indicate an infection. Other signs of post-surgical infection include fever, swelling, and nipple discharge. Immediately contact your veterinarian.

Is it normal for my dog’s nipples to change color during pregnancy or lactation?

Dog’s nipples often change color during pregnancy and lactation. When a bitch is pregnant, the nipples usually enlarge and darken as the blood supply to the area increases. Nursing females can also have darker nipples due to irritation from the teeth and claws of their puppies.

Can excessive grooming lead to blackened nipples?

Excessive grooming of the abdomen can cause irritation that may result in blackened nipples. The increased grooming behavior is likely a symptom of an underlying condition. Talk to your veterinarian about both signs.