Feline Pyometra - A breeders worst enemy
word “pyometra” is derived from Latin “pyo” meaning pus and “metra”
meaning uterus. Feline Pyometra is an abscessed, pus-filled infected
uterus. Toxins and bacteria leak across the uterine walls and into
the bloodstream causing life-threatening toxic effects, without
treatment death is inevitable.
What are the precursors to Pyometra?
Feline Pyometra can be caused from many different things,
with E. Coli and Staph infections being the two main causes.
Classically, the patient is a younger female cat.
Pyometra it’s not nearly as common as one might think. Usually, the
cat has just finished a heat cycle in the previous 1-2 months. She
has a poor appetite and may be vomiting or drinking an excessive
amount of water. In the more usual “open pyometra” the cervix is
open and the purulent uterine contents is able to drip out thus a
smelly vaginal discharge is usually apparent.
There is also a form of feline pyometra called a “closed
pyometra” where the cervix is closed. In these cases, there is no
vaginal discharge and the clinical presentation is more difficult to
diagnose. These patients also tend to be sicker than those with open
pyometra due to retention of the toxic uterine contents. Lab work
shows a pattern typical of widespread infection, which is often
helpful in narrowing down the diagnosis. Radiographs may show a
gigantic distended uterus though sometimes this is not obvious and
ultrasound is needed to confirm the diagnosis. Other reasons are as
It can be promoted from secondary systemic bacterial
infection, post copulation, cystic endometrial hyperplasia, from
estrogen to treat vaginitis, post partum metritis or it can
Below are illustrations of both a normal and Pyometra filed
there an alternative to Surgery?
In the late 1980’s another treatment protocol became
available that might be able to spare a valuable animal’s
reproductive capacity. Here, special hormones called
“prostaglandin’s” are given as injections to cause the uterus to
contract and expel its pus. The main prostaglandin’s used is called
(Lutalyse®). A week or so of hospitalization is necessary and some
cramping discomfort is often experienced. The treatment takes place
over the course of a week. This form of treatment is not an option
in the event of a “closed” pyometra as described above.
PROS: There is a possibility of future pregnancy for
the patient (though often there is too much uterine scarring).
Surgery can be avoided in a patient with concurrent problems that
pose extra anesthetic risk
CONS: feline pyometra can recur. The disease is resolved
more slowly (over a week or so). There is a possibility of uterine
rupture with the contractions. This would cause peritonitis and
escalates the life-threatening nature of the disease. With each heat
cycle, the uterine lining engorges in preparation for pregnancy.
Infection can be activated by hormonal changes during this time.
Eventually, some tissue engorgement becomes excessive or persistent
(a condition called “cystic endometrial hyperplasia”). This lush
glandular tissue is ripe for infection (the inside of the uterus is
sterile, the vagina below is normally loaded with bacteria.). During
estrus the cervix opens and bacteria is allowed to get in. Bacteria
ascend from the vagina and the uterus becomes infected, also getting
trapped as the cervix closes and ultimately pus filled. The warm and
wet environment is perfect for the growing of the bacteria. E-coli
and streptococcus are part of the normal bacteria in the vagina and
are a frequent cause of bacterial pyometra.
There are some important statistics that you should
know about this form of treatment:
1. The success rate for treating open-cervix
Pyometra is 75-90%
2. The success rate for treating closed-cervix
Pyometra is 25-30%
3. The rate of recurrence of the disease is
4. The chances of subsequent successful breeding
What is likely to happen if I do nothing?
The chance of successful treatment without surgery or
prostaglandin treatment is extremely low. If treatment is not
performed quickly, the toxic effects from the bacteria will be
fatal. If the cervix is closed, it is also possible for the uterus
to rupture, spilling the infection into the abdominal cavity. This
will also be fatal.
Article by Gary Fulgham and may not be copied,
reproduced or reprinted without written authorization
Disclaimer: Any medical advice
given here is strictly the author’s opinion, and is not intended as
advice. It is not intended to diagnose or offer treatment for an
individual animal. A qualified Veterinarian should be consulted for
any medical condition.