All You Need to Know About Pyometra in Dogs

What is Pyometra in Dogs?

Pyometra in dogs is a very serious and potentially life-threatening infection in the uterus of female dogs. It’s vital that the condition gets treated rapidly and aggressively.

It typically occurs in older, un-spayed female dogs although it can happen in un-spayed dogs of any age. Typically the only cure when a dog has developed pyometra is emergency surgery to remove the infected uterus.

Read to find out the symptoms, diagnosis, and treatment of this uterine infection in dogs.

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Why Do Dogs Get Pyometra?

Pyometra is a secondary infection as a result of hormonal alterations in a female dog’s reproductive tract. After heat, progesterone levels stay heightened for a few weeks. This stimulates the uterine lining to thicken so that it’s ready for pregnancy.

If pregnancy does not happen for a number of estrus cycles, the lining gets thicker and thicker until cysts might begin to form in the uterus. We refer to this condition as cystic endometrial hyperplasia. 

Fluids get secreted from the thickened cystic lining. This makes it an ideal place for bacteria to grow. Levels of high progesterone also affect the capability of the muscles in the wall of the uterus to contract and get rid of any build-up of bacteria.

White blood cells that typically protect against infection find it harder to enter the uterus during estrus too. This natural factor lets sperm safely get into the female’s reproductive tract. The sperm can do this without getting damaged by the white blood cells.

A combination of all these factors can lead to this life-threatening infection known as pyometra. 

Hormonal Treatments

Progesterone-based drugs can lead to alterations in the uterus that resemble those during the estrus cycle. Synthetic estrogen or estrogen drugs can boost the effect of progesterone on the uterus. 

Drugs containing both progesterone and estrogen occasionally get used when treating particular conditions related to the reproductive system. Any unspayed female receiving hormones should undergo careful monitoring for any signs of pyometra.

The Symptoms of Pyometra

The signs of pyometra in dogs typically begin after 4 to 8 weeks of a heat period. They include:

  • An increase in thirst along with vomiting and nausea 
  • A discharge of pus from the vulva – but this is not always present
  • Frequent panting, tiredness, and a bloated stomach
  • An increase in urination and changes in appetite
  • Collapse

These symptoms might indicate other underlying medical conditions too. You should keep a close eye on your dog and seek the help of a vet should you notice any changes in their behavior.

How Harmful Bacteria Find Their Way Into the Uterus

The cervix leads directly into the uterus. It stays tightly shut other than during estrus when it goes into a state of relaxation to let sperm get into the uterus. When the cervix is open, bacteria typically found in the vagina can get into the uterus relatively easily. 

In a normal uterus, the environment is not conducive to bacterial survival. But, when the uterine wall becomes thickened or cystic, there are perfect conditions for bacterial growth.

During the existence of these kinds of abnormal conditions, the muscles of the uterus are unable to contract in the right way. This can be because of the thickening of the uterine wall or the hormone progesterone. And it means that bacteria that get into the uterus don’t get expelled.

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The Diagnosis Pyometra in Dogs

Your vet will begin making the diagnosis of your dog’s condition by asking questions about the heat cycle. You must let your vet know about any changes to your dog’s behavior, particularly if she starts cleaning herself more than usual in the vulva area.

Your vet will also check for any fluid swelling in your dog’s abdomen through radiographs or more commonly an ultrasound exam. The first phase of pyometra typically comes with a vaginal discharge but no predominant symptoms. Dogs diagnosed with pyometra will go on to display visible symptoms.

Dogs with pyometra also tend to have an increased white blood cell count in the blood. Some dogs may also suffer from a painful, enlarged abdomen.

The Treatment of Pyometra in Dogs

The preferred treatment for pyometra in dogs is surgery. A veterinary surgeon will typically carry out an ovariohysterectomy (spay) to take out the infected uterus and ovaries. The surgery in affected dogs is often more complex than a routine spay.

Dogs diagnosed in the first stages of the illness are usually good candidates for successful surgery. The dangers from complications and extended hospitalization are greater as the pyometra takes hold.

Once the surgery is complete, your dog may need intravenous fluids (IV). You should see pyometra as a medical emergency that requires immediate treatment. 

Non-surgical Treatment

There is a medical approach to treating pyometra as well but the success rate is patchy and comes with considerable risk along with the possibility of long-term complications. 

Prostaglandins are hormones that decrease the blood level of progesterone and lead to the uterus contracting and expelling harmful bacteria and pus. Although they can treat the disease, they are not always successful and have some significant limitations.

They can cause serious side effects, including severe abdominal pain. There also tend to be no clinical improvements after treatment for about 2 days. Very ill dogs in need of immediate life-saving treatment are therefore poor candidates.

Since the uterus contracts due to prostaglandins, it can rupture and spread the infection into the abdominal cavity. This can lead to a  life-threatening condition we refer to as peritonitis. 

The chances of a successful outcome without surgery or prostaglandin treatment are very low. If treatment does not get performed rapidly, the toxic effects from the bacteria are likely to be fatal in the majority of cases. 

Can Spayed Dogs Get Pyometra?

In very rare cases, a spayed dog can get a condition known as “stump pyometra.” This typically happens secondary to the presence of a small quantity of uterine tissue. The tissue may have become accidentally left behind during the original spay procedure. 

Call a Vet Immediately

You may observe symptoms or changes in your dog’s behavior that lead you to believe your dog may be suffering from pyometra. If so, get in touch with a vet straight away. Early diagnosis reduces the risks of further complications.      
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