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Why is there green discharge coming from my female dog in heat?

As a pet parent, you worry when something seems wrong with your dog. After all, they are a part of your family. You probably don’t give much thought to your dog’s vagina, unless you notice something is wrong. 

If your female dog has a green discharge, there are several potential causes. It can indicate a serious infection that requires veterinary treatment. 

Why is there green discharge coming from my female dog in heat?

It’s normal for a dog in heat to have pink or bloody discharge. However, it’s not normal for them to have a green discharge. Green discharge often indicates infection, which can be serious. 


Pyrometra is a uterine infection that occurs in female dogs. It typically occurs in the weeks after they come out of heat. It can occur anytime from 1 to 12 weeks after their heat cycle. 

It’s more common in dogs older than 6 years old, but it can occur in females of any age. 

During heat, the uterus is exposed to high concentrations of hormones. This causes the lining of the uterus to thicken. 

The lining continues to thicken with each heat cycle that doesn’t result in pregnancy. Dogs do not menstruate the way human females do, so they do not shed their uterine lining. 

Over time, cysts develop in the uterus. These cysts secrete fluid, which provides an environment for bacteria to grow. Additionally, the uterus cannot contract properly because of the thickened uterine lining. This prevents the dog’s body from expelling the bacteria. 

The cervix is open during the heat cycle, which provides a pathway for the bacteria to get into the uterus. Normally, white blood cells are in the uterus, which helps prevent infection. 

During the heat cycle, white blood cells are blocked from the uterus, to allow sperm to enter. This allows bacteria to remain in the uterus, causing infection. 

Signs of Pyrometra

The signs of pyrometra will vary based on whether its open or closed. If it is open, your dog will have a green foul smelling discharge. Closed pyrometra is more dangerous, because the pus is not able to drain. 

Signs of open pyrometra include fever and lethargy. Unexplained weight loss and depression may also occur.  

Closed pyrometra causes toxins to enter the blood stream. The dog will become very ill quickly. Symptoms include extreme lethargy, depression, and loss of appetite. Vomitting and diarrhea can also occur. 

Both types of pyrometra typically cause excessive thirst, because the toxins affect the kidneys’ ability to function. A dog with pyrometra will urinate often, and drink excessively to compensate. 

Why is there green discharge coming from my female dog after spay?

You got your female dog spayed, and now you are noticing a green discharge. There should be no discharge after a spay, unless she was in heat at the time. Then, you can expect some slight bleeding. Green discharge after spaying is abnormal, and is usually a sign of infection. 

Uterine Stump Infection

This is an infection in the portion of the uterus that is left. The symptoms are similar to pyrometra, and can include fever, lethargy, and loss of appetite. 

Urinary Tract Infection 

A urinary tract infection can cause green discharge as well. This is an infection of the urinary tract. UTIs are more common after spaying, because she may avoid peeing due to pain. Holding the pee in creates an environment for bacteria to grow, which can lead to a UTI. 

Symptoms of a UTI include peeing very frequently in small amounts, difficulty peeing, and pain when peeing. She may also lick her vulva frequently. Fever and increased thirst are also common with a UTI. 


Vaginitis is much more common in spayed than intact females. It is an infection of the vagina. In addition to discharge, she may experience increased urination, frequent licking, and scooting or rubbing her vagina against objects. The vulva is typically swollen and red. 

Why is there green discharge coming from my female dog’s vulva?

Assuming that she is not in heat, recently spayed, or recently given birth, the green discharge can occur due to a few of the reasons listed above. Let’s take another look at the causes of green discharge coming from the vulva. 


One of the less serious causes of green discharge coming from the vulva is a UTI. A UTI is an infection of the urinary tract, and can affect any dog. 

The symptoms of a UTI include straining to pee, peeing small amounts, and peeing more frequently. She may also have pain when urinating. 


Vaginitis a vaginal infection. It’s fairly common in dogs, and isn’t typically serious. However, it does require veterinary treatment.  She may have increased urination and frequent licking. She may also scoot or rub her vagina against objects. You’ll likely notice that the vagina is swollen and red. 

Why is there green discharge coming from my female dog after giving birth?

The cause of green discharge after giving birth is typically metritis. It’s a serious condition. Without treatment, it can be fatal. 


Metritis is an infection of the uterine lining. It most often occurs in the week after giving birth. It can also be caused by an abortion or unsterile artificial insemination. 

The odds of a female developing metritis increase under certain conditions. These include a prolonged or difficult labor, a large litter of puppies, and retained placentas or fetuses.

 The discharge present with metritis is typically foul smelling and dark green. It may also be mixed with blood. 

Other symptoms include a swollen stomach, dehydration, fever, lack of appetite, and increased heart rate. Diarrhea and vomiting can also occur. She may also become depressed and neglect her puppies due to her illness. Milk production is reduced because her body isn’t functioning properly. 

Metritis Treatment 

Metritis treatment will depend on the severity of the infection, and if you plan to breed her again. Spaying is often recommended. This removes the uterus, and the infection. 

If you want to breed her in the future, the vet can try a more conservative treatment with antibiotics. Antibiotics are also given if a spay is performed, to clear any remaining infection. 

The vet will likely start with a broad spectrum antibiotic, while waiting for test results. When they have a bacterial culture, they can prescribe an antibiotic specifically for that type of bacteria. 

Metritis can be cured if caught early enough. If the infection persists, sepsis occurs. This is a systematic infection that travels through the blood. This can be fatal if not treated. 

Your dog may need to be hospitalized while undergoing treatment. Fluids may be needed to stabilize your dog’s electrolytes. 

What to do about green discharge coming from my female dog?

If you notice green discharge coming from your female dog, you’ll need to get her to the vet. Any cause of green discharge in females requires veterinary treatment, although some are more serious than others. 

If she has severe lethargy, weight loss, fever, or bloody discharge, you should get her to the vet immediately. If she has milder symptoms or only discharge, it’s not as urgent. However, she should still visit the vet within the next few days. 

Note any symptoms your dog is experiencing, and when the symptoms started. This information can help your vet make a diagnosis.