My Dog's Nipple is Leaking - Types and Causes of Discharge

By Josie F. Turner, Journalist specialized in Animal Welfare. Updated: March 5, 2019
My Dog's Nipple is Leaking - Types and Causes of Discharge

See files for Dogs

Our dog's overall health and well-being is down to many factors. One of the most important elements is ensuring that we, as guardians, pay close attention to any physiological changes. If we see that our dog's nipple is leaking, then we will understandably grow concerned. Discharge from a dog's nipple isn't normal, but there are various causes which can explain its occurrence. Some of these are more troubling than others, but all of them require us to look at the dog's current state. We will also look at what different types of discharge might reveal about the underlying cause. Keep reading AnimalWised to discover the various reasons my dog's nipple is leaking and what we might be able to do about it.

You may also be interested in: My Male Dog Has a Swollen Nipple

My dog's nipple is leaking white liquid

If you are worrying about discharge from your dog's nipple, one of the first things to consider is their sex. Both female and male dogs have nipples, but only the females are strictly functional. This is because they use them to nurse their young after birth and before they are weaned onto solid food. Male dogs have nipples which are essentially vestigial. All mammal embryos begin as female, it is only later on that maleness develops[1]. Male dog nipples are a leftover element of this experience.

With female dogs, there are different considerations to make if you see discharge from their nipple. The most important factor is pregnancy. Some people may think that a dog will only lactate after they have given birth. However, pregnant female dogs can start the lactation process a few days or even a week before they give birth to their litter. In these cases, the discharge will be of a clear or milky consistency.

The cause of milk production, is a neuropeptide known as oxytocin which “is produced in the paraventricular and supraoptic nuclei in the hypothalamus and is known to stimulate milk ejection during breastfeeding and uterine contractions during labor”[2]. If the dog starts releasing oxytocin earlier, then milk production may begin earlier also. We should know not to touch or squeeze the lactating dog's nipples. This is because doing so could interrupt the process or even cause infection which can be passed on to the weaning puppies.

While we might think of discharge due to lactation as only being white in color, it is also normal to see a slightly yellow discharge occurring before birth. With any type of nipple leaking in female dogs, it is only problematic when the dog is not pregnant, nor have they recently given birth.

IN cases where the female dog is not pregnant, but they are showing signs as if they were, we may be encountering a false pregnancy. Clinical pseudopregnancy in dogs is a “syndrome observed in non-pregnant dogs and is characterized by clinical signs such as nesting, weight gain, mammary enlargement and lactation”[3].

My Dog's Nipple is Leaking - Types and Causes of Discharge - My dog's nipple is leaking white liquid

Pseudopregnancy in female dogs

If we see that our female dog looks as if she is lactating or there is a white or yellowish discharge from their nipples, we need to know if she is pregnant. If she has been sterilized and has had no contact with a male dog, then it is likely, but we will still need to take them to the vet for an accurate diagnosis. The same study quoted above claims that canine pseudopregnancy (sometimes known as false pregnancy) could be caused by higher concentrations of prolactin (the protein related to milk production), but also discusses the role of progesterone in prolactin production.

Canine pseudopregnancy occurs between 6 and 12 weeks after a dog's estrous cycle where these hormone levels rise. Physical and behavioral symptoms of a dog with pseudopregnancy include:

  • Nesting (finding a comfortable spot as if she were to raise pups)
  • Digging
  • Weight gain or anorexia
  • Mammary gland enlargement
  • Aggression
  • Over-protectiveness
  • Excessive licking
  • Lactation
  • Mothering of objects

The last symptom on this list usually involves a toy. The dog will mother it as if they were their own offspring and take it somewhere to look after them. Their aggression might come when you try to take this object away as the dog can defend it as if it were their own. Some female dogs might go into a state of depression during a pseudopregnancy.

Physically, the dog's abdomen may enlarge and, in rarer cases, vomiting and diarrhea might occur. Again, we should not manipulate the breasts as it can lead to infection and other problems. Mastitis (something we'll look into further below) can occur which results in inflammation and can be painful. The symptoms of pseudopregnancy in dogs usually leave on their own accord. However, it can come back after another estrus cycle ends. In these cases, it is highly recommend the dog is sterilized.

My Dog's Nipple is Leaking - Types and Causes of Discharge - Pseudopregnancy in female dogs

My dog's nipple is leaking yellow fluid

As we stated above, it is possible for some yellowish discharge to occur prior to lactation in female dogs. However, there are other types of yellow discharge which might be more concerning. If it occurs shortly after the mother has given birth, it could be a case of acute septic mastitis. This is because the puppies can agitate the nipples during suckling and allows bacteria to enter the nipple.

Affected female dogs will have a fever, become depressed and may refuse food. Infected and swollen breasts are usually the ones closest to the groin area. They may become painful and take on a bluish color. The yellow discharge is due to the infection. Hygiene is also an important factor as dogs in unclean environments may have an increased risk of developing bacterial infection. The dog's milk may contain a little blood or take on a yellowish color. However, it is possible for the breasts to be enlarged, but the milk is still a white color.

Dogs which have just given birth might also develop mastitis due to galactostasis. This is the “overload of the mammary gland with milk that is seen before the parturition [giving birth] or shortly afterwards”[4]. Due to the enlargement, the milk is unable to be let-down and the result is mastitis. Other cause of mastitis in dogs include mammary gland tumors and mammary gland hyperplasia (the latter being a kind of benign tumor).

Treatment of mastitis will depend on the cause. In case of infection, antibiotics will normally be prescribed. However, if the cause is galactostasis then the first course of treatment should be to prohibit feeding. In terms of tumors, whether malignant or benign, surgery will most likely be undertaken. If the mastitis is left untreated, the result could be gangrene or even death.

My Dog's Nipple is Leaking - Types and Causes of Discharge - My dog's nipple is leaking yellow fluid

My dog's nipple is leaking blood

If your dog is leaking blood from their nipples, it won't always look red like fresh blood. Instead, the color might be coffee brown or similar. As we stated above, it is possible that mastitis will be accompanied by blood leakage. However, there are other causes which need to be considered.

If your dog has a dark brown or reddish liquid leaking from their nipple, but it is not fresh, it may be due to the presence of a tumor. This can occur in one or several of the dog's breasts. Both cancerous and non-cancerous tumors can cause lumps to occur. It will require an examination and tests by a vet to determine if a lump is cancerous.

With breast cancer in dogs, the main symptom is a painless mass that sometimes causes ulceration of the skin and bleeding. This type of tumor runs the risk of metastasis to other parts of the body, especially the lungs. The treatment requires surgery, although it will depend on how far the disease has progressed. There is a much higher breast cancer risk in unsterilized dogs, only one of the important reasons for sterilization. We should also pay attention to any changes in our dog's breast tissue, especially in dogs over six years of age. If we detect any leakage, inflammation, pain or hard lumps, we need to take our dog to the veterinarian.

Blood leaking from a dog's nipple might have a less life threatening reason. Abscesses can occur when the dog has an injury or a foreign body has entered the skin. These may have a mixture of blood and/or yellowish or green discharge. The abscess grows as pus becomes trapped underneath. The abscess may leave on its own accord, but it does rub the risk of further infection or becoming septic. For this reason, it is important to go to the vet for treatment.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to My Dog's Nipple is Leaking - Types and Causes of Discharge, we recommend you visit our Other health problems category.


Write a comment

Add an image
Click to attach a photo related to your comment
What did you think of this article?
My 1 year old female pitbull has been leaking blood from her nipples. it first started when she finished her first heat cycle. First it was only one nipple and then all of them. We got her fixed. Most of them stopped bleeding. but the few that didn't are still leaking blood. The blood has dried and basically hangs out of her nipples. She has been vomiting. No pain to the touch or swollen. We took her to the vet for it and they gave her some ointment, but they aren't helping. Could this be mastitis?
My xl bully has swollen nipples and has bled one spot from 1 nipple any idea?
Linda Little
My 9year old daschound produced milk to feed stray kitten. Now her nipples have milk,clear and dark liquid that I have gently pushed out?
Administrador AnimalWised
Hi Linda,

If your dog is not pregnant, they shouldn't produce milk. If they do, it could be due to a false pregnancy. However, due to your description, it may even be a disease, some of which can be dangerous. We recommend speaking to your veterinarian.
brandie bradford
Hi I have a 3 year old chihuahua and about 3 weeks now her bottom two nipples have been leaking . she's not getting fat or acting any different she let's us touch them and she has been eating and drinking the same. she goes everywhere with us and she hasn't got hung up with any dogs. I just don't know what to do she doesn't have a fever i just don't know what to do next because she can't see her doctor for 2 more weeks.
My German Shepherd male dog has an inverted nipple and it recently started producing pus. I'm really worried about him. He also has a lot of allergies. He is on prescription drugs doxycycline, cetrizine hydrochloride and chlorpheniramine maleate. I cannot reach any vet due to the current curfew in our country.
David Daniel
My dog has stopped nursing and act as it hurts when she does nurse her nipples are also swollen shown In pic I've se
Administrador AnimalWised
Hi David,

We know it is very difficult given the lockdown situation, but you should still be able to call your local veterinarian to explain the symptoms and be advised.
Crystal D McCarter
I have a Maltipoo that just started to leak white fluid from her nipples she we got her last November she isn't even a year old yet. Every one in the house thinks she is pregnant but I'm the skeptic . She spends more time with me than anyone else and I haven't seen any sign of pregnancy. Her nips are the same size nothing else is different other than the fluid
Administrador AnimalWised
Hi Crystal,

Domestic dogs can reach sexual maturity as little as 6 months, so it is possible. This is particularly the case with smaller animals. However, knowing why this is happening will require diagnosis from a vet.
Cheryl Bing
My 6yro recently desexed female staffy has white liquid coming from nipples, she had one litter 4yrs ago.
Administrador AnimalWised
Hi Cheryl,

As we have shown in the article, there are various reasons why this might be, but we cannot diagnose any of them. You will need to take them to a vet for appropriate diagnosis and treatment. Good luck!
My Dog's Nipple is Leaking - Types and Causes of Discharge
1 of 4
My Dog's Nipple is Leaking - Types and Causes of Discharge

Back to top