Pyometra is a deadly condition that affects unspayed female dogs and cats. It happens when the uterus becomes infected and is filled up with pus. This is often a result of hormonal changes during the reproductive cycle. 

In dogs and cats, pyometra is more common in middle-aged to older females, but it can occur in younger animals as well, especially those that have gone through multiple heat cycles without mating. 

Types of Pyometra

The condition is often categorized into two types: open and closed pyometra.

Open Pyometra

In this form, the cervix remains open, allowing pus and other discharge to exit the body through the vaginal canal. This can make the condition easier to detect, as owners may notice foul-smelling discharge, often accompanied by lethargy and a loss of appetite. 

Open pyometra is generally less immediately life-threatening because the infection can drain, reducing the risk of uterine rupture.

Closed Pyometra

In closed pyometra, the cervix is sealed, trapping pus and infection inside the uterus. This form is more dangerous because the infection cannot escape, leading to rapid toxin buildup in the bloodstream. 

The swelling uterus can also rupture, causing internal bleeding and widespread infection, which are life-threatening emergencies. Closed pyometra is harder to diagnose early because there is no visible discharge, and symptoms may appear more suddenly.

How Does Pyometra Develop?

Pyometra usually develops after a heat cycle when the hormone progesterone increases to prepare the uterus for a possible pregnancy. During this time, the uterine lining thickens and produces secretions.

If no pregnancy occurs, the uterus may retain these secretions, creating an ideal environment for bacterial growth. The most common bacteria involved in pyometra is Escherichia coli, which can go from the vagina to the uterus.

Hormonal imbalances also play a key role. High levels of progesterone suppress the immune response in the uterus, reducing its ability to fight off infections. This combination of hormonal changes and bacterial contamination is a buildup of pus and inflammation, essentially pyometra.

If pyometra is left untreated, it can progress quickly and cause further problems. That’s why it’s crucial to keep regular checkups to detect potential issues like pyometra. Early detection and immediate vet treatment are important steps to take to prevent any further problems.

Risk Factors for Pyometra

Pyometra is a potential disease for any unspayed female dog or cat. However, there are certain factors that can increase the risk of this disease. Here are the risk factors for pyometra:

Age and Reproductive History

The risk of pyometra increases with age. The most commonly affected dogs and cats are those who are middle-aged. Additionally, pets who have gone through multiple heat cycles without mating are also more susceptible.

Each heat cycle exposes the uterus to hormonal changes that can lead to the thickening of the uterine lining, creating a favorable environment for infection over time.

Breed Predisposition

Some breeds are genetically predisposed to developing pyometra. Dog breeds such as Rottweilers, Bernese Mountain Dogs, and Cavalier King Charles Spaniels are known to have a higher risk. Purebred cat breeds like Sphinx, Ragdoll, and Siamese may also have an increased likelihood due to genetic factors or anatomical differences.

Hormonal Treatments

Treatments that are used to suppress heat cycles and prevent pregnancy are called hormonal treatments. These treatments can also increase the risk of pyometra. Because of the synthetic progesterone or estrogen of these drugs, they can cause hormonal imbalances in dogs and cats.

With an imbalance of hormones, the uterus will be exposed to these hormones for an extended period. This results in a dog’s and cat’s immune system weakening, making them vulnerable to a bacterial infection.

Weakened Immune System

Dogs and cats with compromised immune systems. A weaker immune response reduces the body’s ability to fight off infections, making it easier for bacteria like E. coli to establish and spread within the uterus.

Symptoms of Pyometra

The signs and symptoms of pyometra can differ based on whether the type is open or closed. However, there are general signs that can be indicators of the disease. Here are the symptoms of pyometra you should take note of:

General Symptoms

Both dogs and cats affected by pyometra may show common symptoms of the disease. Some of the common signs include lethargy, loss of appetite, and a decline in activity. You can also notice fever in the early stages, with pets developing a lower body temperature if sepsis happens.

Increased thirst and excessive urination are also common as the kidneys struggle to filter toxins caused by the infection. Vomiting and diarrhea are also possible, which can also lead to dehydration in return.

Dogs and cats can also become more withdrawn and irritable because of the discomfort they feel. You’ll see them seek out places where they can rest and be alone. They’ll lose all interest in physical activities as well.

Symptoms of Open Pyometra

When the cervix is open, one of the most obvious signs of pyometra is a foul-smelling vaginal discharge. The discharge can range in color from yellowish to reddish-brown and is often accompanied by a noticeable odor. Owners may observe staining on bedding or around the tail area. 

Dogs and cats with open pyometra may lick their genital area excessively, trying to clean the discharge. While these symptoms make open pyometra easier to identify, the infection can still spread rapidly.

Symptoms of Closed Pyometra

Closed pyometra presents a greater challenge because the cervix remains sealed, preventing visible discharge. Pets with this form often appear sicker, as the infection and toxins are trapped within the uterus. Abdominal pain, swelling, or bloating are more pronounced.

You may notice your pet’s abdomen becoming distended as the uterus fills with pus. Pets may show severe lethargy, have difficulty standing or walking, and, in some cases, collapse due to septic shock.

Diagnosing Pyometra in Cats and Dogs

Diagnosing your dog’s or cat’s condition will involve a series of steps to get an accurate diagnosis. In turn, your input and observations will also lend a hand in allowing our experts to diagnose your pet. Here’s what is involved in diagnosing pyometra:

Veterinary Examination

We will start by examining your pet’s medical history while performing a thorough physical examination. Our vets will ask you questions about your pet’s recent heat cycles and anything you have observed that is out of the ordinary.

Blood Tests

Blood tests are essential in diagnosing pyometra and assessing the overall health of your pet. A complete blood count often reveals elevated white blood cell levels, a sign of infection. These tests can also detect kidney issues, which are common for pets with pyometra.

Imaging Techniques

If we’re to diagnose pyometra, an ultrasound is one of the technologies we will use.  This device allows us to visualize the uterus and detect the presence of fluid, which will confirm the condition.

In cases of closed pyometra where the external symptoms are less obvious, ultrasound is particularly valuable. X-rays may also be used, especially if the uterus is significantly enlarged, although they are less sensitive than ultrasound for detecting fluid buildup.

Treatment for Pyometra

Once pyometra has been diagnosed, the treatment process is straightforward. With the most effective option being surgery, supportive care treatments will also be included to ease up your dog’s or cat’s experience.

Ovariohysterectomy

The most common and effective treatment for pyometra is an ovariohysterectomy, also known as spaying. This procedure will surgically remove the infected uterus and ovaries, eliminating the source of the infection and preventing recurrence.

During the surgery, our veterinary surgeons will carefully remove the uterus to prevent rupture and the spread of infection. For closed pyometra, where the risk of uterine rupture is higher, the surgery must be performed with extra caution. 

General anesthesia is used, and post-operative care includes monitoring for complications like infection, pain management, and ensuring the pet regains strength.

Surgery is the definitive treatment and is highly recommended for most cases, as it not only cures the condition but also removes the risk of future uterine infections. Recovery time varies, but most pets regain their energy within a few weeks with proper care.

Medical Management

Antibiotics are prescribed to control the bacterial infection, and prostaglandins or other medications are used to contract the uterus and expel its contents. While this can temporarily resolve the infection, it does not prevent recurrence because the uterus can still have an infection. 

Pets treated medically will require close monitoring and regular checkups with our vets to ensure that the medicines have done their jobs.

Supportive Care

Throughout the whole treatment process, supportive care treatments will be given. This may include IV fluids to combat dehydration, medications to reduce pain and swelling, and nutritional support you can bring at home.

The Role of Spaying and Neutering Against Pyometra

Spaying your dog or cat is the most effective way to prevent pyometra. By removing the ovaries and uterus, the source of the infection is eliminated entirely. Spaying is typically recommended for female dogs and cats that are not intended for breeding. 

The procedure can be performed as early as six months of age, although the timing may vary based on breed and individual health considerations. So, if you think you’d be okay with removing your dog or cat’s ability to reproduce, consider spaying to protect them.

Conclusion

Pyometra is a condition can affect unspayed female dogs and cats. The combination of a bacterial infection and hormonal imbalance make it difficult to deal with. To help protect your pets, consider spaying them, as these provide long-term benefits and protection.