Canine Pyometra, Everything You Need To Know

What is a pyometra? The name defines itself: “pyo” (pus) and “metra” (uterus). In its simplest form, it is an infection of the uterus. 

What causes pyometra?

It is a combination of hormonal changes and bacterial overgrowth within the uterus’s lining. As the female dog continues to undergo several heat cycles, the lining of the uterus progressively becomes persistently or excessively thickened. This continuous thickening over time contributes to the formation of cysts. Bacteria ascend from the vulvovaginal tissue onto a cystic uterus, creating the perfect environment for infection.

What are possible signs of pyometra?

A pyometra may occur in any intact female, usually in middle to old age. The clinical signs depend greatly on whether the cervix is open or closed. If the cervix inflammation is not severe, then there is room for the purulent discharge to exit the body, thus causing an open pyometra. Discharge stains could be noted on furniture or on skin/fur around the vulva, and the discharge could be quite foul-smelling. There may or may not be signs of lethargy or reduced appetite.

In a closed pyometra, the cervix lining is too thick, and infection begins to accumulate and distend the uterus, almost like a balloon filled with water. The accumulation of bacteria and toxins causes these dogs to become ill rapidly. A distended belly can be noticeable, and they will have a reduced appetite and become very lethargic.

With either an open or closed pyometra, vomiting and/or diarrhea may be present as well as drinking an excessive amount of water.

If a dog that has not been spayed presents to a veterinary clinic with these clinical signs, a pyometra will be on top of the list for differentials.

Bloodwork, x-rays and ultrasound are helpful tools used to confirm the diagnosis of pyometra. On bloodwork, a pattern of widespread infection could be seen, signs of dehydration as well as elevation in kidney values, among other changes. Radiographs can show a severely enlarged and distended uterus occupying most of the abdominal cavity. At times that distention is not readily apparent, and ultrasound can help confirm the diagnosis with more specific imaging.

Pyometra Treatment

Surgical removal is the ideal treatment, especially for dogs with closed pyometra, as these patients tend to be toxic. Before and during surgery, antibiotics are given to correct the systemic infection, and these pets tend to be hospitalized for a couple of days to correct dehydration and manage post-operative pain.

If treatment is not performed in a timely manner, the toxic effect of the bacteria can prove fatal. In closed pyometras, the infection can accumulate to the point of rupturing the uterus, causing spillage into the abdominal cavity.

Preventing Pyometra in Dogs

The single and most important thing to do to never run the risk of pyometra formation is to have your dogs spayed. Small to medium-sized breed dogs can be spayed as early as six months. For large to giant breed dogs, having them spayed closer to the year of age is recommended.

If you have any questions or concerns during this time, please do not hesitate to contact us here at Metro Paws Animal Hospital. We are always happy to help you!