My Take Tuesday: The Parsimonious Pyometra

Apart from preventing unwanted pregnancy and pet overpopulation, routine spaying of female dogs has been historically recommended for two reasons: 1) Reduce the incidence of mammary cancer, and 2) Prevent the female from developing pyometra later in life. This is caused by a bacterial infection of the uterus resulting in a potentially fatal infection.

The word pyometra can be divided into two root words: Pyo meaning pus and Metra referring to the uterus. A pyometra starts after a dog goes through a heat cycle, usually within about 2 to 5 weeks. A pyometra develops due to repeated prolonged exposure of the estrogen-primed uterus to progesterone (estrogen increases the number of progesterone receptors in the endometrium). Female dogs are prone to uterine disease due to the unique nature of cycling in this species. As infection develops in the uterus, the uterus fills with pus. The most common bacteria isolated in these cases is E coli. The uterus with a pyometra can be huge! I have surgically removed an infected uterus weighing over 11 pounds from a 56-pound Golden Retriever.

The clinical signs associated with this disease are anorexia, depression, drinking and urinating more frequently, abdominal distention, and sometimes a vaginal discharge is noted. Vomiting and diarrhea may also be present, especially late in the course of the disease. If any of these clinical signs are noted in your pet – immediate veterinary consultation is imperative.

Females that develop pyometra have an underlying condition called cystic endometrial hyperplasia. Most intact females older than 5-6 years have some degree of this. Most cases are treated by removing the infected uterus and ovaries. This surgery is very difficult and much more expensive than a traditional spay. There are many more post-operative complications that may arise that are not associated with a routine spay.

These include:

Peritonitis – is the inflammation of a thin layer of tissue inside the abdomen. It’s a medical emergency, and it’s often caused by infection.

Disseminated intravascular coagulation – a clotting disorder that is often fatal.

Sepsis – occurs when chemicals released in the bloodstream to fight an infection trigger inflammation throughout the body. This can cause a cascade of changes that damage multiple organ systems, leading them to fail, sometimes even resulting in death.

It is simple to avoid this. Females not intended for breeding should be spayed at a at a relatively young age. Females used for breeding should be closely monitored by both the owner and the veterinarian.

There is not a one-size-fits-all recommendation about what age is best to spay and neuter. Studies suggest different ages for different breeds. It is important to discuss these recommendations with your veterinarian and develop an individualized plan for your pet. 

If you are hesitant to spay your pet because of the cost of the routine surgery, you must consider the cost of an emergency pyometra surgery also. Such a surgery is at least 3-5 times higher than what a routine spay would be.

At Mountain West Animal Hospital, we discuss both the benefits and detriments of routine spays and neuters and strive to help you make the best decision for the health and well-being of your individual pet. You can count on us as a trusted partner in the care of your four-legged family member.

And that is my take. 

N. Isaac Bott, DVM