Why is my dog leaking milk?

Milk production is normal in all mammals. It is usually associated with nursing but can also be related to stress, illness, injury, or hormones. Like any other female animal, dogs produce milk that is released via their nipples.

Most of the time, it is caused by an actual or perceived pregnancy, although it may also be caused by a variety of conditions. Dogs may generate milk or what seems to be milk from their nipples even though they’re not pregnant or have just given birth. 

This can happen for various reasons:

  • False pregnancy is when a dog’s body mistakenly thinks it is pregnant and starts to produce milk. A fake pregnancy may develop in a dog regardless of whether she was mated or not. False pregnancy symptoms often appear three weeks to two months after the last heat cycle and resemble actual pregnant symptoms. 
  • Mammary Gland Tumor – A tumor on the pituitary or ovaries can also cause milk production. A mammary gland tumor is a lump or growth on your dog’s breasts. Breast cancer is rare in dogs, so most mammary tumors aren’t cancerous. However, some do become malignant. If you notice a lump or swelling in your dog’s breast area, contact your veterinarian right away.
  • Hypothyroidism can cause some dogs to lactate. In rare cases, it can be genetic. Hypothyroidism is a condition in which the thyroid gland does not produce enough hormones. Symptoms can include excessive weight gain, hair loss, and a poor coat.
  • She has mastitis – Some breeds of dogs are prone to mastitis, which is inflammation of the breast tissue. The condition can cause pain, fever, and swelling around the affected area. If your dog has mastitis, she may start to produce milk.
  • It could be a hormonal imbalance. For example, if she’s being spayed or neutered, this will cause changes in hormone levels. If she’s not spayed or neutered, her hormones may just be out of whack.

Should I be worried? What do I need to do about my dog producing milk?

There are many possible causes of milk production in dogs, but the most common one is a false pregnancy. If you think your dog may be producing milk, take her to the veterinarian for a check-up. The vet can determine the cause and recommend the appropriate treatment.

The least dangerous of the disorders is hypothyroidism. It is not curable, but it can be treated, and a dog with medication hypothyroidism may enjoy a normal and healthy life. Your dog’s veterinarian will provide thyroxine, an oral hormone replacement that she will be required to take for the rest of her life.

Tumors of the mammary gland will need to be surgically removed, potentially followed by chemotherapy or, less frequently, radiation. Following therapy, the owner should ensure that the dog’s mammary glands are checked on a monthly basis for tumor recurrence.

If there is no evidence of disease, then your dog will likely continue to produce milk for several months following treatment. If you notice that your dog is producing more than usual, consult your vet immediately.

When drugs are required, hormones that suppress prolactin (the hormone responsible for milk production) are now the best options. These drugs can result in abortion if the dog is found to be pregnant, therefore it is critical to be certain. Metergoline acts in a way to suppress prolactin but may also be used to terminate false pregnancy. It takes around 4-5 days of medication to stop the lactation and bring everything back to normal.

Sometimes, you can use home remedies to treat mastitis and mild cases of pseudopregnancy. For example, cabbage leaves reduce swelling and pain by cooling off the area, reducing inflammation. If your dog is diabetic or has heart problems, smoking the leaves is not recommended.

Your veterinarian can also prescribe antibiotics if mastitis is diagnosed. If the cause of the lactation is unknown, your vet may do some tests (x-rays, blood work, etc) to determine the underlying problem.

The consequences of lactation in dogs have reduced calcium levels, which can lead to bone problems. Lactating dogs should be given plenty of fresh water and a diet that is low in sodium. Owners of lactating dogs should monitor their pet’s weight and look for any signs of dehydration. If your dog is producing milk, contact your veterinarian for information about how to best care for her.


Is it normal for my dog to produce milk?

Yes, it is normal for some female dogs to produce milk. The mammary gland which produces milk remains active after the mother dog has stopped feeding her pups.

Can nipples produce milk when not pregnant?

The nipple cannot produce milk unless stimulated by the hormone prolactin. The hormone prolactin is what stimulates the production of milk. However, if a female dog is pregnant and then gives birth, her mammary glands must be stimulated by the hormone prolactin in order to produce milk.

How can you tell if a dog is having a false pregnancy?

The best way to know if a dog is having a false pregnancy is several different signs of the pregnancy, such as swollen nipples and mammary glands. However, two of the most common ways to tell that a female dog is going through a false pregnancy are that her estrogen levels rise and she may begin lactating.

Is it dangerous for my dog to produce milk?

Yes, if a female dog is producing more milk than normal, it is important to consult a veterinarian. Excess milk production can lead to dehydration, weight loss, and mammary gland tumors.

Can a dog’s nipples get infected?

Yes, nipples can become infected. If a dog’s nipples are red, swollen, and painful, she may have an infection. Consult your veterinarian if you think your dog may have an infection.

Can I give my dog antibiotics to stop milk production?

Antibiotics are only effective in treating the infection that may have caused the milk to be produced. If the cause of the lactation is unknown, your vet may do some tests (x-rays, blood work, etc) to determine the underlying problem. If antibiotics are prescribed, it is important to complete the entire course of treatment.

What do you do if your dog has a false pregnancy?

If your dog is having a false pregnancy, there is not much you can do to stop it. The best thing you can do is to make sure she has a comfortable place to rest and plenty of fresh water. If your dog begins lactating, contact your veterinarian for information about how to best care for her.