Overview
Pyometra is a severe bacterial infection of the uterus that
occurs in unspayed female dogs and cats that can be potentially life
threatening.
When a pet is in heat, the dominant hormone affecting the
uterus is estrogen. At the end of the heat cycle, estrogen levels drop and
progesterone (another hormone) levels rise. Over the course of several heat
cycles, progesterone can cause changes in the uterine lining, such as thickened
tissue and cysts. This creates the ideal environment for bacteria to flourish.
Pyometras occur when bacteria ascend from the vagina into
the uterus and multiply. The body attempts to fight off the infection by
sending white blood cells to the uterus, which creates the fluid buildup.
Pyometra is described as being “open” or “closed.” With an “open”
pyometra, the cervix (the portion of the uterus that connects with the vagina)
is open. The fluid that forms in the uterus as a result of the infection can
drain through the vagina and out of the body.
When the cervix is closed, as in “closed” pyometra, the
fluid in the uterus cannot drain through the vagina, so it builds up,
stretching the uterine walls and can potentially rupture the uterus. If this
occurs, the infection spreads to the abdomen and can spread into the
bloodstream leading to septic shock and often resulting in death. A pyometra
can weigh as much as 10 pounds.
The
top picture is a normal uterus during a routine spay surgery and the lower
picture is an emergency pyometra removal surgery.
The condition is most common in older, unspayed female dogs
that have never had a litter, but it can occur in any female dog or cat that
has not been spayed. The youngest dog that Swaim’s veterinarians have diagnosed
was 9 months old. In
dogs, pyometras are most likely to happen
in the first few weeks to months after a heat cycle.
Symptoms
and Identification
Pets that have open pyometra may or may not have a
foul-smelling white, yellow, or blood-tinged discharge from the vagina.
Otherwise, the signs can be somewhat vague, such as:
·
Lethargy (tiredness)
·
Loss of appetite
·
Vomiting
·
Increased drinking and urinating
·
Abdominal swelling or “bloated”
appearance
·
Fever – which may or may not be
present
Your veterinarian will most likely recommend bloodwork and
abdominal x-rays (radiographs) to visualize the uterus. Occasionally, an
abdominal ultrasound may be needed to get a better view of the uterus.
Treatment
Spay (surgical removal of the uterus and ovaries) is the
best treatment for a pyometra. In most cases, this is an emergency surgery that
must be performed before the uterus ruptures or the infection spreads to other
parts of the body. Because it is a more complicated surgery than a typical spay in
a healthy dog or cat, it will most likely be more expensive. The pet may also
need IV fluids and antibiotics.
Prevention
Early spaying of female pets prevents pyometra.
This article has been adapted from Vetstreet.
