Pyometra Flashcards
In what age and stage of estrus does pyometra usually occur in dogs?
unbred, middle-aged to older bitches during diestrus when estrogen-rimed endometrium comes under the influence of progesterone.
what pathology may be occurring concurrently with pyometra?
cystic endometrial hyperplasia
How does progesterone lead to the development of pyometra?
progesterone increases susceptibiltiy to bacterial infections by induced fluid accumulation in endometrial glands and uterine lumen, suppressing leukocyte activity, and decreasing myometrial activity.
what are the clinical signs associated with pyometra?
Lethargy
Anorexia / Hyporexia
Fever
Dehydration
Vomiting / Diarrhea
Polyuria/Polydipsia
Pain on abdominal palpation or abdominal distension
+/- presence of purulent or hemorrhagic vaginal discharge
Lameness (hindlimb or sacral pain)
tachypnea, tachycardia
what would u expect to see on CBC/Chem for pyometra case?
- leukocytosis (d/t neutrophilia) +/- left shift +/- toxic changes
- normocytic / normochromic anemia
- hyperglobulinemia
- hyperfibrinogenemia
- increased hepatic enzymes (AST, ALP)
- azotemia
- electrolyte inbalances
all consistent with inflammation +/- toxemia
what bacteria is most commonly associated with pyometra?
E. coli
others may include: B-hemolytic strep, staph pseudintermedius, and other enterbacteriales (proteus)
secondary invaders are spore-forming anaerobes such as clostridium, as well as NSF anaerobes too.
why can you not diagnose pyometra via swab of discharge from posterior vagina?
there is NF of the vagina so there results are not significant.
You can only collect from vaginal discharge if you suspect open pyometra, collected it with a guarded swab, or collect from the anterior vagina (near the cervix)
what is the BEST sample to take to diagnose pyometra?
- FNA of surgical sample (once you’ve removed the uterus, use that sample)
Do you need to do c/s for a suspected case of pyometra, why or why not?
yes – because E. coli (the most common culprit) is not predictably susceptible
what causes PU/PD in pyometra cases?
E. coli endotoxin interferees with action of ADH on renal tubules. You get medullary washout and isosthenuria.
There is also often a mild interstitial and tubular nephritis.
urinalysis with culture is always a good idea bc a lot of these dogs also have cystitis.
what are common differentials for suspect case of pyometra?
- endometritis
- metritis
- vaginitis
- sepsis
what are risk factors for pyometra?
- irregular cycles
- exogenous hormones
- older, nulliparous bitches
T/F: CEH causes irreversible changes to the endometrium
true
this can lead to infertility, pregnancy losses, reduced litter sizes, embryonic resorption, endometritis, hydrometra/mucometra, and pyometra
if you take xrays of a pyometra case, what would you be likely to see?
- fluid filled uterus
double bladder sign
if you do ultrasound of a dog with suspect pyometra, what would you likely see?
fluid-filled uterus
moderate endometrial inflammation (thickened uterine wall)
+/- CEH signs
when is a vaginal cytology indicated for suspect pyometra?
if its open pyometra.
you can see PMNs, vaginal epithelial cells, bacteria, and proteinaceous debris
note this does not confirm pyo alone, you must also see fluid in the uterus and clinical signs.
T/F: closed pyometra is usually associated with more severe illness
true
what are the 3 main antibiotics used in pyometra cases?
- amoxicillin/clavulanic acid
- enrofloxacin
- trimethoprim/sulfa
caution with empirical use because there are issues with antimicrobial resistance. so use Abs based on culture.
what type of supportive care treatments would you do for a pyometra case?
- fluids
- gastroprotectants (ondansetron, cerenia)
- NSAIDs
- analgesia
- antiemetics
what does medical therapy entail for pyometra?
- empty uterus – PGF2a (uterine contractions, luteolysis, cervical opening)
- decrease progesterone (aglepristone – progesterone-receptor blocker)
- luteolysis (cabergoline – prolactin inhibitor/dopamine agonsit)
- antibiotics
- gastroprotectants
- analgesia & NSAIDs
continuous monitoring of: progesterone levels, ultrasound, CBC/Chem and blood gas.
Recommend she be bred on the next cycle, then OHE.
this takes 3-5d for improvement.
___________ is a progesterone competetitive antagonist
alizin (aglepristone)
_____________ is a synthetic prostaglandin that has few side effects.
Estrumate (cloprostenol)
__________ is a natural prostaglandin that causes smooth muscle action, luteolysis, and myometrial contractions, but has a narrow therapeutic index.
Lutalyse (dinoprost)
_______ stops prolactin feedback for better luteolysis.
cabergoline
When should you STOP medical therapy in pyometra cases?
- confirm luteolysis is complete (progesterone <2 at least)
- uterus is empty and there is no vaginal discharge
- systemically improved
what are 2 anesthetic concerns associated with surgical therapy for pyometra?
- hypotension (d/t large loss of fluid)
- electrolyte and renal derangements
what are prognostic indicators for pyometra?
- sepsis
- endotoxemia
- hypercoagulable state
- MODS
- DIC
T/F: surgical tx of pyometra is best for refractory cases or non-breeding animals
true
