Reproductive system diseases

My Dog Has a Swollen Vulva - Causes and Treatment

By Eva López. March 21, 2023
My Dog Has a Swollen Vulva - Causes and Treatment

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We rightly associate a a swollen vulva in dogs with their heat period. This is because increased production of estrogen causes inflammation of the vulva, a process designed to attract males and indicate they are ready for fertilization. This does not explain why a spayed dog will have a swollen vulva, although they can also experience increased estrogen production in rare cases. It is important to know that various physiological processes can result in a swollen vulva and/or vagina in spayed or intact female dogs. This is known as vulvovaginitis and it can be associated with pathological issues such as infections, tumors or even prolapse. Without prompt intervention, some of these causes can be fatal.

At AnimalWised, we want to provide a thorough overview of why my dog has a swollen vulva. We discover the causes and treatment of vulvovaginitis in dogs so you can have an idea of what to expect if your dog suffers from any of these issues.

  1. My dog's vulva swollen and bleeding
  2. My dog has a swollen vulva, but is not in heat
  3. My dog has a swollen and red vulva
  4. My pregnant dog has a swollen vulva

My dog's vulva swollen and bleeding

When discussing the reasons why a dog's vulva is swollen, it is very important we distinguish between a dog that has been spayed and one that is reproductively intact. If your dog is between 6 months to 1 year in age, vulval swelling with slight bleeding is likely a sign they are experiencing their first heat period.

Scientifically known as the estrus cycle, there is no exact way to determine when your dog will have her first heat cycle. It will only occur once they have reached sexual maturity, something which tends to happen earlier in smaller dog breeds, but which can also be influenced by many other factors.

In addition to observing swelling and bleeding, there are other symptoms which will likely accompany a dog's first heat cycle. They include:

  • Being more receptive to males
  • Actively seeking males during walks
  • Males approach excitedly to smell privates
  • Darkening of the vulva
  • Frequent licking of the vulva

Spaying in dogs is a process which usually entails a full ovariohysterectomy, i.e. the removal of the uterus and ovaries. This processes should prevent the levels of estrogen production which result in a swollen vulva. If your dog has not been spayed, then problems which affect the ovaries and uterus can result in vulval inflammation. These are important to distinguish between normal symptoms of heat in dogs:

  • Ovarian cysts: although there are several types of ovarian cysts, the most common are functional. These cysts cause a state of constant estrus, making it appear as if the dog were in permanent heat. If 40 days after the first bleeding the dog continues to have an inflamed vulva which bleeds, it is advisable to go to the veterinarian to carry out the correct diagnostic tests or rule out the presence of ovarian cysts. Surgical intervention is the required treatment.

  • Ovarian tumors: while cysts are more common in younger dogs, tumors more often develop in dogs over the age of 5 years. Some ovarian tumors also develop cysts, so it is possible that both can be concurrent. They are not usually very common in female dogs, although they are a possible reason why your dog has a swollen vulva. They will need to see a veterinarian since tumors can be malign and result in the death of the dog.

  • Pyometra: a uterine infection that presents the secretion of mucus that may be accompanied by blood as its main symptom. Although these other causes of a swollen vulva in dogs can result in discharge from the area, pyometra has characteristic thick, transparent or whitish discharge which can be bloody. If the dog reaches this point, the condition is probably in an advanced state and a vet should be seen immediately as it is potentially fatal.

  • Presence of foreign bodies: if a foreign body enters the dog's vaginal cavity and causes lesions either in the vagina or on the vulva, vulvovaginitis is common.

  • Ovarian remnant syndrome: although very unlikely, it is possible for a spayed dog to bleed from her vagina. It shows the symptoms of a dog in heat, even though they have been sterilized. It is caused by inadequate removal of the reproductive organs during spaying as a part of the ovaries remains. This cause estrogen to be produced and the dog to show signs of heat.

Learn more about these issues in female dogs with our article on why a dog has clear discharge.

My Dog Has a Swollen Vulva - Causes and Treatment - My dog's vulva swollen and bleeding

My dog has a swollen vulva, but is not in heat

When heat has been completely ruled out as a cause of the dog's swollen vulva, we can look at other pathological processes which can result in canine vulvovaginitis. The following are some of the most frequent causes of vulval inflammation in dogs:

  • Infection: vulvovaginitis is so called because it refers to the swelling of both the vulva and the vagina. Infections are a common cause of this issue, but some can affect one reproductive organ more than the other. This depends on various factors, but especially the origin of the infection. For example, if bacteria is introduced from the outside, the vulva will likely become inflamed first, although it will eventually spread to the vagina. If a foreign body enters the vagina, it may not affect the vulva as it may not cause a problem until it enters further into the vagina. Severe urinary infections in dogs can cause inflammation of the vagina which may extend to the vulva, although only once advanced. Finally, urine or fecal matter can enter the vulva and introduce bacteria which causes swelling.

  • Uterine prolapse: this is a condition which is characterized by an inflammation of the vulva which eventually sees the uterus emerge through the vagina and vulva. As the prolapse progresses, the more of the uterus will emerge. We will also see other symptoms in the dog such as listlessness and apathy. You should go to the veterinarian as soon as you see any signs of potential prolapse. It most often occurs in dogs which have had several litters, but it can occur in dogs which have never given birth.

  • Vaginal prolapse: at first, the signs are the same as a uterine prolapse. In this case, it is the muscles and tissues of the vagina which emerge through the vulva. It may appear as if there is a growth on the dog's vagina. It will be the veterinarian who will determine the cause. Although not considered a medical emergency, treatment is required as prolapse risks secondary infection. It can be reversed with hormone therapy, but may require surgery.

  • Womb (uterine) infection or ovarian infection: as we have seen in the previous section, pyometra does not always present bleeding, so if the vulva is swollen and the discharge of pus or thick discharge is observed, a specialist should be seen to check if it is this pathology and start treatment.

  • Trauma: caused by a blow or injury that can cause bleeding in addition to vulval inflammation.

The image below shows a uterine prolapse.

My Dog Has a Swollen Vulva - Causes and Treatment - My dog has a swollen vulva, but is not in heat

My dog has a swollen and red vulva

The type of inflammation can help to indicate why a dog has a swollen vulva. If we see discharge in the form of mucus or blood, it might be one of the causes listed above. If the vulva is swollen or irritated, but the dog shows no other clinical signs, it may be due to an allergic reaction. This is especially the case when we see small bumps on the dog's private area.

Due to the location of a dog's vulva, it is common for them to come into contact with the ground. If there is something on the ground which can be an allergen, it can result in contact dermatitis on the vulva and consequent swelling. Chemical substances are some of the most common allergens, but it will depend on the individual dog. There is also thought to be a genetic influence in atopic dermatitis in dogs.

Although dermatitis usually appears as inflammation alone, it is possible for wounds to appear. This is due to the dog excessively licking or rubbing the area due to itching. When this occurs over an extended period of time, it results in the already sensitive skin breaking. Secondary bacterial infections can occur. Although allergic dermatitis cannot be cured, the symptoms can be alleviated with corticosteroids or antihistamines. To prevent it occurring, the allergen needs to be determined and removed from the dog's environment.

Redness and swelling of the dog's vulva can also be a result of something known as vaginal hyperplasia. When in an advanced state, it can cause the vulva to swell. It usually occurs in unsterilized dogs under 5 years of age. It is an excessive reaction to estrogen production and worsens if not treated. It can also lead to vaginal prolapse, so veterinary consultation is imperative once signs are observed.

My Dog Has a Swollen Vulva - Causes and Treatment - My dog has a swollen and red vulva

My pregnant dog has a swollen vulva

It is understandable a dog's guardian will be especially concerned when their animal is pregnant. Although not common, complications of a dog's pregnancy can occur and we need to be observant for any possible signs of a problem.

Fortunately, inflammation is normal when the due date is approaching. One of the signs a dog is about to give birth is when the dog has a swollen vulva. This can occur 2 or 3 days before labor begins. We will also likely see other signs such as the dog preparing a nest for delivery or an agitated attitude. A dog's pregnancy lasts between 59 to 67 days, so a swollen vulva at his time likely indicates they are about to give birth.

If your pregnant dog has an inflamed vulva, but there is still some time before labor should occur, it may be due to a complication. To determine the cause, we will need to take them to a veterinarian. Causes can include uterine rupture or an obstruction. Some dogs are more susceptible such as brachycephalic dog breeds.

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 Has a Swollen Vulva - Causes and Treatment, we recommend you visit our Reproductive system diseases category.

  • Hermos, G. A., Rimavicius, F., & Gonzalez, D. Tumors of the female reproductive system in canines and cats (ovary and uterus). National Council for Scientific and Technical Research.

  • Esquivel Lacroix, C. Alterations of the reproductive system of the bitch.

  • Carlos Sorribas, M. V. Most frequent reproductive diseases in female dogs.

  • Avila Garcia, J., & Cruz Hernández, G.E. Vaginal prolapse and uterine prolapse. Faculty of Veterinary Medicine and Zootechnics of the National Autonomous University of Mexico.

  • Gonzalez, K. Vaginal hyperplasia and prolapse in bitches. Published in Argentine Veterinary Magazine.
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My Dog Has a Swollen Vulva - Causes and Treatment