24, 25, 26: fail to become detect preg - canine pyometra to end Flashcards
approximately how many breeding bitches will get canine pyometra?
2 in 400
why is canine pyometra a less common problem now what it used to be?
it is a well understood dz and is preventable, so is much less common overall now than it used to be
what is the definition of pyometra?
more than just pus in the uterus…..
a disease complex that includes the progression of:
cystic endometrial hyperplasia, mucometra (=hydrometra), endometritis and pyometra complex
what is the classic presentation for canine pyometra?
- middle aged, nulliparous FM
- late estrus 4-8 wks ago
- often treated w steroids for birth control
- treated w abx during previous heats
- gradual onset of dz
what is nulliparous?
never had offspring
what steroids are used to treat bitches for birth control?
- progestagens and estrogens
what is the role of progestagens in birth control?
to suppress estrus
what is the role of estrogens in birth control?
“morning-after” treatment for mismated bitches
how does the administration of p4 and e2 during pro estrus pre dispose the bitch to developing pyometra?
when p4 is added to suppress estrus, at a time when she is under the influence of e2, they have a synergistic effect on the endometrial glands and they produce excess ‘milk’
when there is no embryo present to consume the milk, it accumulates in the uterus -> cystic -> mucometra -> hydrometra
if a bitch presents with pymoetra and is not “classic”, meaning she is young and recently had a litter, what specifically should you ask about?
ask if she was treated with anti microbials when she was in heat last
why do some treat bitches with anti microbials while in heat?
some think bitch has better chance of conceiving if she is treated during estrus
some uneducated owners of male studs will demand the bitch be treated before mating to prevent spread of STI’s - which is incorrect b/c they do not exist in animals like they do in people and most pathogenic dzz would be spread by the male anyways….
what does giving a bitch antimicrobials while in estrus achieve?
selects for more resistant bacT and oftne more pathogenic bacT - to grow in her reproductive tract and wipes out commensal healthy bacT
what do you suspect happened to a young bitch that presents with pyometra and has an unusual bacT that is highly resistant to drugs?
she was probably given antimicrobials during her last heat cycle
what are c/s of bitch with pyometra?
lethargy dec appetite free fluid at time of preg diagnosis distended, tender abdomen enlarged lnn dehydration anemia
s/t (sometimes):vaginal discharge
PU/PD
vomit/diarrhea
collapse
in the bitch, why does vaginal discharge occur s/t but is often uncommon at time of onset of pyometra?
b/c she is still under the influence of p4, which holds the cervix closed
how does endotoxemia occur sometimes in the bitch with pyometra?
endotoxins are absorbed from the uterus -> affect uterus function -> cause PU -> PD as a result of the PU
only in about 1/3 of the cases
why do some bitches vomit and have diarrhea with they have pyometra?
b/c they are toxemic
if left unattended, why does a bitch with pyometra collapse?
multi organ failure occurs as result of endotoxemia -> death can occur if not treated
if free fluid is seen in the uterus of the bitch 3 weeks post breeding, what does that indicate is likely to occur?
pyometra
why might a bitch with pyometra experience hyperthermia followed by hypothermia?
hyperthermia - fever - due to infection
hypothermia in later stages - due to severe shock
when does peripheral lymphadenopathy occur in a bitch with pyometra?
3-4 wks after inoculation / initial infection by the time you see her
when / why does a bitch with pyometra experience anemia?
chronic infection
due to toxemia
what precaution must be taken if palpating abdomen of bitch with suspected pyometra?
palpate enlarged uterus
be cautious - b/c if the cervix is shut, the increased pressure from your palpation will put pus into the utero tubal junction and into peritoneal cavity -> pyometra becomes peritonitis [pyo abdomen]
what is a better alternative than palpating the uterus of a bith with possible pymoetra
u/s
when examining a bitch with pyometra, what do you see when conducting a vaginoscopy?
pus in the anterior vagina
what is seen on cytology from a bitch with pyometra?
many NTs, toxic NTs, NTs with phagocytossed bacteria
what use is culture for a bitch with pyometra?
more use if trying to preserve her breeding ability instead of spaying her - in this case, she needs to be treated medically instead of surgically
is difficult to do though, b/c you will get some resident bacT from anterior vagina
must know what is there in order to know how to kill it
what types of bacT tend to show up on culture of bitch with pyometra?
MC vaginal bacT
mostly opportunistic infection
70% e. coli
may see Proteus, staphs, klebsiella, pseudomonas, some anaerobes
t/f
a lab work up of blood work is necessary to definitely dx pyometra in bitch?
false
lab work is only necessary if you cannot make the dx based on hx and presentation
what chances to WBCs will be seen in bitch with pyometra?
acute and chronic changes
acute: neutropenia
chronic: neutrophilia with left shift
on CBC of pyometra bitch, why might hematocrit be increased? decreased?
inc: dehydration
dec: anemic
what does a urine specific gravity of a bitch with pyometra indicate?
supports PU
why might knowing a bitch’s BUN prior to Tx for pyometra be of value?
we may use potentially nephrotoxic drugs so knowing her kidney function ahead of time would be helpful
t/f
it is common to evaluate IgG and look for hypergammaglobulinemia in a bitch with pyometra
false
hypergammaglobulinemia will be seen in chronic cases of pyometra - not measured specifically or very often
how is pyometra diagnosed in the bitch?
- anamnesis
- uterine distention
- vaginal discharge
- leukocytosis
- cytology
- u/s
t/f
x rays are a common modality used to dx pyometra as well as other soft tissue dzz in the abdomen
false
u/s is better
x ray was used in past but should not be used anymore for soft tissue dzz
what is the best and most common treatment for canine pyometra?
ovariohysterectomy
t/f
canine pyometra is urgent and considered an emergency - surgery must be planned for that day
true
t/f
to reduce the risk of rupture and leakage, a small incision should be made to remove the uterus from, similar to a spay incision
false
incision should be very liberal and large so the uterus is not squeezed or handled roughly to be removed
t/f
during a spay of a pyometra bitch, the entire uterus and cervix is removed
true
how might peritonitis occur during surgery to treat pyometra?
- leakage through uterine tubes and into the abdomen
- rupture of uterus
what might occur if a stump of uterus with pus is left behind in a bitch?
stump pyometra or stump granulomas
what tissue should you ligate through to prevent stump granuloma from occurring?
the anterior vagina
t/f
it is necessary to stabilize the pyometra bitch before conducting surgery
false
not really appropriate b/c she is so toxic, she needs immediate supportive care and to head straight to surgery to remove the source of infection
what is the medical treatment of pyometra in bitch?
luteolysis
abx
fluids
NSAIDs
what luteolytic agent is MC used to Tx pyometra in bitch?
PgF2a
why is luteolysis a successful Tx for canine pyometra?
removes source of p4 which allows cervix to open so pus can drain when uterus is squeezed
when selecting which PgF2a drug to use for pyometra in the bitch, is chlorprostenol or luteolyse [dinoprost] a better option?
luteolyse is better b/c in a study with chlorprostenol, one dog died so if a dog you treat with it dies and the owner sues you, lawyers will find this study and use it against you
what are 3 appropriate dose regimens for dinoprost / luetolyse for tx of pyometra in bitch?
- 50 ug/kg BID s/c 1 day
- 100 ug/kg BID s/c 1 day
- 250 ug/kg BID s/c 5 days
what dose regimen for dinoprost / luteolyse is NOT appropriate for use b/c it is experimental and would leave you vulnerable as a practitioner?
why might some consider using it?
10 ug/kg QID s/c 7-10 days
it has no side effects
why are high doses of PgF2a required for luteolysis in a bitch?
risks?
very high doses required b/c canine CLs are very refractory to PgF2a
many side effects will occur to make bitch sick
t/f
RU 486 (algepristone or Mefipristone) is a readily available drug that is used commonly to cause lyteolysis in dogs with pyometra
false
RU 486 is illegal for use in animals in US b/c it is used for human abortions
used readily in Europe
in addition to lysing the CL, what other function does PgF2a have in canine pymoetra Tx?
it also serves as an ecbolic agent
what is MC antimicrobial used to tx canine pyometra?
side effects?
gentocin and penicillin
aminoglycoside => nephrotoxic
in addition to gentocin and penicillin, what other antimicrobials are used to Tx canine pyometra?
amoxicillin
clavulinic acid
enrofloxacin [less toxic than aminoglycosides]
in what way might steroids be used in some cases of pyometra?
shock doses of steroids if the bitch is very bad and you need immediate action to save her life -> this will stabilize her, then you can operate in 2 days
what is the prognosis for a pyometra bitch after medical therapy?
recurrence and fertility?
not great
10-30% recurrence
10-50% fertility [volkman says up to 80% fertility in his experience]
t/f
after experiencing pyometra and medical treatment, a bitch should not be bred in her next heat cycle
false
she SHOULD be bred in her next heat cycle - do NOT leave her uterus empty for another cycle
t/f
if after medical tx for pyometra a bitch is bred but fails to become pregnant, you should be concerned about persistent infection
false
persistent infection is unlikely
you should be concerned that the endometrium was damaged and that it might not be able to support a pregnancy
in an unspayed bitch, what is necessary in order to get pyometra?
steroidogenic priming of the uterus
what drugs are available as contraception in bitches?
megestrol acetate (ovaban) mibolerone
how does megestrol acetate work in the bitch?
put the bitch on the drug when she is in anestrus and does not have e2
how does mibolerone work in the bitch?
androgenic drug - testosterone like
suppresses HPA
**best Tx
what tumor occurs MC in the uterus?
lyommyoma - tumor of smooth muscle