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Pyometra 855

○ Midstream urine sample is likely to be • If only PGF 2a is used, it is critical to start with
contaminated by vaginal discharge. low doses to minimize ecbolic effect of the
VetBooks.ir Advanced or Confirmatory Testing rupture). After the cervix opens, the dose Diseases and Disorders
drug until the cervix opens (risk of uterine
can be incrementally increased depending on
• Culture and cytology of vaginal discharge
○ Cytology findings (degenerate poly-
is the desired effect of treatment.
morphonuclear cells and phagocytized patient tolerance, and evacuation of uterus
bacteria) often indistinguishable from ○ Natural PGF 2a : dinoprost tromethamine
other causes of vaginal discharge (e.g., (Lutalyse)
foreign object, vaginitis) ■ Dose of 10-15 mcg/kg q 8h for 1 day
○ Bacterial culture: usually detects normal SQ; 25 mcg/kg q 8h for 2 days SQ;
vaginal flora (often E. coli), and bacterial 50-100 mcg/kg q 8h for 3 days SQ
culture is therefore important only for appro- ■ Dose can be adjusted; some animals are
PYOMETRA Lateral abdominal radiographic image. priate antibiotic choice and not diagnosis. more sensitive and react with more side
Note the fluid-filled uterus (arrow). (Used with permis- Sample for culture should be collected from effects, but it is rare to see side effects
sion from Krekeler N, et al: Pyometra. In Monnet E, the cranial vagina with a guarded swab or at these low, incrementally increased
editor: Small animal soft tissue surgery, Ames, IA, 2013, from the uterus with the use of endoscope. doses. Others may need doses up to
Wiley-Blackwell, pp 625-634.) • Additional blood tests 100 mcg/kg for 2-3 days to evacuate
○ Serum progesterone usually > 2 ng/mL uterus effectively.
○ Prostaglandin F 2a (PGF 2a ) metabolites ○ Synthetic PGF 2a analog cloprostenol
useful to rule out hydrometra and muco- ■ At higher dosages, it can have side
Differential Diagnosis metra (elevated only in cases of pyometra) effects; stimulates less uterine con-
• Uterine enlargement tractions, prolonging resolution of
○ Pregnancy: ruled out by ultrasonography TREATMENT pyometra compared with natural form
performed > 25 days after the luteinizing of PGF 2a
hormone (LH) peak Treatment Overview ■ Convenience of q 24h administration,
○ Mucometra or hematometra: not associ- • Complete ovariohysterectomy (OHE) is the reported to be effective if given at a
ated with systemic clinical signs and treatment of choice for any animal that is dose of 1-2.5 mcg/kg q 24h for 10 days
neutrophilia not intended for breeding. (started with 1 mcg/kg)
• Systemic clinical signs • Medical management is recommended ○ Side effects of PGF 2a are dose dependent
○ Polyuria/polydipsia (pp. 812 and 1271) only for young (<4 years), valuable breed- and diminish after several injections.
○ Abdominal discomfort or distention ing animals without significant systemic ■ Side effects (i.e., tachypnea, vomiting,
(p. 21) illness. diarrhea, urination, and anxiety) start
• Vulvar discharge (p. 1045) about 20 minutes after treatment and
Acute General Treatment last for about an hour.
Initial Database Medical management: ■ Walking the bitch for 15 minutes
• Diagnostic imaging • Medical treatment can be used on closed- after administration seems to alleviate
○ Ultrasonography is strongly recommended. cervix pyometra cases using appropriate side effects; should be hospitalized
The uterine horns are convoluted and filled pharmacologic agents and protocols. for at least 1 hour after treatment for
with anechoic to hypoechoic fluid (± floc- • The rationale of medical treatment is to observation
culation); uterine wall can be thickened, remove progesterone and to eliminate ■ Animals should not be fed before PGF 2a
and cystic endometrial hyperplastic bacteria from the uterus. treatment but rather an hour after side
changes may be visible • To evacuate the uterus, the cervix needs effects have disappeared.
○ If abdominal radiography is performed, to be open. If bitch has a closed-cervix • Misoprostol (synthetic PGE1 analog)
fetal ossification is visible only after day pyometra, it is paramount to immediately ○ PGE1 causes uterine contractions and
42, and distinction of uterine enlargement initiate a treatment protocol that removes cervical relaxation, thereby assisting
between pregnancy and pyometra is not the influence of progesterone and opens in evacuation of pus from the uterus.
possible earlier. the cervix. Aglepristone (Alizin) is drug of However, misoprostol does not have a
• CBC choice because it does not cause uterine luteolytic action, so it must be combined
9
○ Leukocytosis (>35 × 10 /L) common; contractions so the risk of uterine rupture with aglepristone and/or a PGF-2a.
neutrophilia with left shift (± toxic change) is low. ○ Oral dose 10 mcg/kg PO once. Vomit-
○ Decreased white blood cell count may be ○ Aglepristone is a progesterone antagonist ing can occur after oral administration.
observed due to pooling of neutrophils that competitively prevents progesterone Or,
inside uterine lumen. binding to its receptor, which results in ○ Dissolve tablets in saline (200 mcg for
• Biochemistry luteolysis without uterine contractions. bitches < 20 kg and 400 mcg for bitches
○ Hyperproteinemia, hypergammaglobu- ○ Works well in combination with PGF 2a > 20 kg) and deliver intravaginally using
linemia, hypoalbuminemia, hypercho- in open- and closed-cervix pyometra cases a long soft pipette to deposit the PGE1
lesterolemia, and elevation of C-reactive ■ In closed-cervix pyometra, aglepristone as close to the cervix as possible.
protein level should be given first to induce luteolysis • Dopamine agonists: cabergoline; prolactin
○ Increase in serum liver enzymes, azotemia and cervical opening; cervical opening antagonist
(response to sepsis and dehydration) occurs 26 hours (± 13 hours) after first ○ Cabergoline 5 mcg/kg PO q 24h for 7-14
○ Electrolyte imbalances (if vomiting and aglepristone injection. days; can be used 25 days after ovulation
diarrhea) ■ Aglepristone 10 mg/kg SQ given twice to treat pyometra
• Urinalysis 24 hours apart; can follow with injec- ○ Cabergoline is most effective when used
○ Bacteriuria, glucosuria, isosthenuria and tion 8 days later with PGF 2a because it potentiates the
proteinuria ■ PGF 2a treatment can be started 24 hours luteolytic effect and results in rapid decline
○ Cystocentesis under ultrasound guidance after the last injection of aglepristone in progesterone (<24-48 hours).
to minimize risk of uterine puncture to accelerate uterine evacuation. ○ Cabergoline has minimal or no side effects.

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