Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

462 •DOG OWNER’S HOME VETERINARY HANDBOOK
There are two types of pyometra: open and closed. In open-cervix pyometra,
the cervix relaxes and releases a large amount of pus that often resembles
tomato soup. These bitches usually do not appear as ill as those with closedcervix
pyometra.
In closed-cervix pyometra, the undrained uterus enlarges, often producing
a painful swelling in the lower abdomen. This type of pyometra is more likely
to be accompanied by vomiting and diarrhea, and may produce signs of toxicity
such as high fever, rapid pulse, and shock. The diagnosis of closed-cervix
pyometra is made by an X-ray of the abdomen showing an enlarged uterus.
Ultrasonography distinguishes pyometra from the enlarged uterus of pregnancy;
an X-ray taken after about 45 days of pregnancy will also distinguish one from
the other.
Treatment: Pyometra requires immediate veterinary attention to prevent
shock and death. Ovariohysterectomy, along with antibiotics, is the treatment
of choice. It is best to do this operation before the bitch becomes septic.
When it is important to preserve the reproductive potential of a valuable
bitch, an alternative to ovariohysterectomy can be considered—provided that
the cervix is open and the bitch is not septic. It involves the use of antibiotics
along with prostaglandin. Prostaglandin PGF 2a (Lutalyse) relaxes the cervix,
stimulates uterine contractions, and evacuates the pus. Lutalyse is administered
by subcutaneous injection daily for three to five days. If evacuation is not
complete, a second course is given. Antibiotics are selected based on sensitivity
tests, and are continued for one to three weeks after evacuation of the
uterus. Lutalyse is not licensed by the FDA for use in small animals, but is nevertheless
widely used for this purpose.
Prostaglandin treatment is accompanied by a number of dose-related side
effects, including shock. Uterine rupture may occur when the cervix is closed.
Most veterinarians regard closed-cervix pyometra as a contraindication to the
use of Lutalyse.
Bitches who recover from pyometra are at increased risk for developing it
again on subsequent heat cycles. They should be bred on the first estrus after
recovery to maximize their chances for fertility.
ENDOMETRITIS
Endometritis is a low-grade bacterial infection of the uterus that occurs as a
sequel to a postpartum infection of the uterus (see Acute Metritis, page 483),
and occasionally as a result of vaginitis that ascends to the uterus. Endometritis
is a significant cause of female infertility. Unlike pyometra, the infection is
limited to the lining of the uterus. Little pus is produced, but the endometrium
becomes inflamed and harbors bacteria. This creates an unfavorable environment
for fertilization and the implantation of embryos.