Is It Normal For Stuff To Come Out Of Dogs Nipples?

Discharge from dogs’ nipples is a fairly common occurrence that can be completely normal or a sign of an underlying medical issue. Understanding the causes of nipple secretions in dogs is important for pet owners to determine when it might indicate a health problem needing veterinary attention.

Nipple discharge can occur in both female and male dogs. While secretions are normal for a lactating female, any nipple discharge in a spayed female or male dog should be evaluated. Some potential causes are minor, like dirt causing irritation, but abnormal discharge can also result from more serious conditions like cancer.

Veterinarians say it’s a good idea for owners to do routine checks of their dog’s nipples and note any secretions. That allows pet owners to identify changes from the normal state. By informing themselves on this topic, dog owners will know what to watch for and when to seek veterinary care. This knowledge ultimately aids in keeping dogs healthy and detecting issues early on.

Anatomy of Dogs’ Nipples

Both male and female dogs have nipples located along two mammary gland lines extending from their groin area up to the chest area. According to the veterinary anatomy resource ImaiOs, nipples are known as “papillae mammae” in medical terminology.

The ImaiOs veterinary anatomy page on nipples notes that dogs normally have 5 to 10 nipples in each mammary gland line. The nipples are connected to mammary glands under the skin that produce milk to feed puppies after giving birth.

Normal Nipple Secretions

It is common for unspayed female dogs who are not pregnant or lactating to have some nipple discharge. This discharge is usually clear or milky in color. According to, the source of this fluid is likely ovarian hormones that stimulate the mammary glands.

This nipple discharge can occur regularly with the dog’s heat cycle. The fluid may be more noticeable right before or after the heat period when hormone levels fluctuate. As long as the discharge is not bloody or pus-like, it is usually considered normal.

Male dogs may also have a bit of clear or milky nipple discharge, even if they are neutered. Small amounts are not a concern. However, any sudden increase in amount, color change, or foul odor could indicate a potential health issue.

Abnormal Nipple Discharge

While some nipple discharge can be normal in unspayed or pregnant dogs, abnormal nipple discharge can indicate an underlying health issue. Bloody, pus-like, or unusually colored discharge is not normal and requires veterinary attention.

According to, bloody or pus-like discharge could signal an infection like mastitis. Mastitis is inflammation of the mammary glands, usually caused by a bacterial infection. It causes the mammary gland to become swollen, hot, and painful. The nipple may discharge bloody, purulent material. Mastitis requires prompt veterinary treatment with antibiotics and anti-inflammatories [1].

The Spruce Pets notes green, black, or brown discharge could indicate the presence of tumors in the breast tissue. These abnormal growths can obstruct the mammary ducts and lead to unusual nipple discharge. Breast cancer may also result in bloody or unusual discharge from the nipples and requires rapid diagnosis and treatment [2].

In short, any nipple discharge that contains blood or pus, or is an odd color like green, black, or brown merits rapid veterinary assessment. These abnormal secretions likely signal an infection, inflammation, or potentially cancerous changes in the breast tissue.

Causes of Abnormal Discharge

There are several potential causes of abnormal nipple discharge in dogs:

Infection – One common cause is mastitis, which is an infection of the mammary glands. This causes inflammation, swelling, and often a discharge from the nipples. Mastitis is most common in unspayed female dogs and can occur after pregnancy and nursing puppies. It is often treated with antibiotics (PDSA).

Trauma – Injury or trauma to the mammary glands can also cause nipple discharge. This may occur from the dog being hit or bumped in the chest area. The impact can damage mammary tissue and ducts, allowing fluid to leak out. Applying cold compresses and allowing time to heal may resolve minor trauma.

Tumors – Both benign and malignant mammary tumors can lead to nipple discharge. Tumors may physically damage and block ducts or stimulate fluid production. Malignant tumors are a serious concern, as they can metastasize and spread cancer. Any suspicious lumps or discharge warrants veterinary investigation (The Spruce Pets).

When to See the Vet

You should take your dog to the vet if you notice any signs of infection or illness related to nipple discharge, including:

  • Swollen, red, painful, or warm nipples or mammary glands (
  • Nipple discharge that is bloody, purulent, or foul-smelling (
  • Lethargy, loss of appetite, vomiting, or other signs of systemic illness
  • Multiple nipple discharges or discharge from abnormal nipples
  • Nipple or mammary gland lumps, especially if they are growing or ulcerated (

Any nipple discharge in a spayed female dog should also be evaluated by a vet. Left untreated, conditions like mastitis can progress to a more serious infection that requires aggressive treatment. It’s important to have any abnormal nipple discharge checked out promptly.


If a dog is experiencing abnormal nipple discharge, the vet will perform a thorough physical exam to look for any abnormalities. They will visually inspect and palpate the mammary glands, feeling for any masses, inflammation, or tenderness that could indicate a problem. According to VCA Animal Hospitals, the vet will likely perform cytology by collecting samples of the abnormal discharge with a needle and syringe and examining the cells under a microscope. This can help determine if malignant cancer cells are present. If cancer is suspected, the vet may recommend a biopsy to obtain mammary gland tissue for further analysis and confirm a diagnosis. During biopsy, the vet surgically removes small pieces of tissue from the mammary glands and analyzes them. Biopsy results can differentiate between benign and malignant tumors.



Treatment for abnormal nipple discharge in dogs will depend on the underlying cause. Some common treatments may include:

Antibiotics – If there is an infection causing the discharge, such as mastitis, antibiotics will likely be prescribed to fight the infection. Antibiotics may be given orally or by injection. It’s important to give all doses as prescribed, even if symptoms improve, to fully clear the infection.

Anti-inflammatories – Medications like steroids may help reduce inflammation and discomfort associated with conditions like mastitis. Reducing inflammation can help limit damage to breast tissue.

Surgery – If there is an underlying tumor or growth causing discharge, surgery may be necessary to remove it. Surgery can prevent the abnormal tissue from spreading or turning cancerous. The type of surgery will depend on the location and specifics of the growth.

In some cases, a combination of treatments may be utilized. Your veterinarian will recommend the best course of action based on your dog’s specific condition, age, and other factors.


There are a few steps dog owners can take to help prevent abnormal nipple discharge in their pets:

Spaying dogs, especially before their first heat cycle, can significantly reduce the risk of mammary tumors which are a common cause of nipple discharge according to this source. Spaying eliminates heat cycles and the hormone fluctuations that can contribute to mammary tumors.

Avoiding trauma to the breasts can also help prevent issues. Be careful not to let dogs jump on or off high objects which could lead to injury. Also use a harness instead of a leash attached to a collar to reduce strain on the chest when on walks.

Cleaning the underside of female dogs regularly can help identify any nipple changes early on. Look for signs of swelling, discharge, redness, or pain which may indicate a problem. Regular checks allow for early treatment.

Maintaining a healthy diet and weight can support mammary health. Obesity and poor nutrition increase inflammation which can contribute to tumor development according to VCA Animal Hospitals.


In summary, while some nipple discharge in dogs is normal, abnormal discharge or swelling can indicate an underlying medical issue that requires veterinary attention. It’s important for dog owners to routinely monitor their dog’s nipples and mammary glands for any abnormalities. Discharge, swelling, pain, and redness should prompt a vet visit. With proper monitoring and care, many nipple conditions can be effectively treated or managed before they become more serious problems.

Nipple health is an important part of a dog’s overall wellbeing. Being aware of what’s normal for a dog’s nipples, recognizing abnormal changes early, and seeking prompt veterinary care can help prevent minor issues from escalating into larger ones. By keeping an eye on their dog’s nipples and getting veterinary advice when concerned, owners can ensure their pet’s comfort and quality of life.

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