Dog Therio (UP to parturition) Flashcards
where is semen deposited in female dogs
fornix
what is the orientation of the vestibule in relation to the vagina in dogs
vestibule vertical and vagina horizontal
what covers dog ovaries
ovarian bursa
in dogs, the cervical opening is often (parallel/perpendicular) to the vaginal canal
perpendicular
what is unique about the eggs ovulated by bitches and why does this matter
immature on ovulation and take 48h to become mature; implications in timed AI
do canine oocytes have a longer/shorter lifespan relative to some other species
longer
what hormone do we use to predict ovulation timing in bitches and why
progesterone; it begins to rise prior to ovulation
what are the 4 stages of the canine estrus cycle and what stage(s) are “heat”
proestrus, estrus, diestrus, anestrus
proestrus and estrus = heat
are bitches seasonal or non-seasonal breeders
non-seasonal
puberty is marked by when the first ________ occurs
proestrus
what is the average and range of puberty in bitches? does it occur earlier in large or small breeds
average: 8-14 months
range: 6-26 months
earlier in small breeds
what are 4 ways to determine stage of estrus in bitches
1) vaginoscopy
2) vaginal cytology
3) progesterone levels
4) receptivity/behaviour
what is the average length of proestrus in the bitch and when does it start
9 days; starts with first drop of blood
what is the level of progesterone and estrogen during proestrus in the bitch
low (baseline) progesterone; estrogen rising
what type of cells are present during proestrus in the bitch
parabasal and intermediate
what are cues of proestrus on vaginoscopy in bitches
thickening and edema of the vaginal epithelium
what are external cues of proestrus in bitches
non-receptivity to males but increased aggression towards and mounting of other bitches; vulvar swelling; serosanguinous vaginal discharge; may start flagging
what happens to the hormone profile (progesterone, estrogen) during estrus in the bitch
progesterone rises at LH surge, continues rising at ovulation then stays elevated
estrogen peaks at LH surge then starts to decline
what is the average length of estrus in bitches
9 days (same as proestrus)
what are 4 key things that happen during estrus
1) LH surge
2) ovulation
3) fertile period
4) breeding (standing heat)
the LH surge occurs ______ hours before ovulation in bitches
48h
what are 2 methods to estimate the timing of the LH surge
1) progesterone
2) witness LH test
progesterone tests are run using (serum/plasma), which requires what color tube
serum; red top
what types of cells are present during estrus in bitches
cornified epithelial cells (anuclear or superficial)
what is the appearance of the vaginal epithelium (using a vaginoscope) during estrus and how does this differ from proestrus (in dogs)
estrus: crenulation (raisins)
proestrus: edema (grapes)
what causes the serosanguinous discharge observed during heat in bitches
diapedesis of red blood cells (NOT hemorrhage)
what is the average length of diestrus in bitches
2 months
diestrus in bitches occurs __ days after LH surge and __ days after ovulation
8; 6
how does the vaginal epithelium appear during diestrus in bitches?
flat; less layers since no estrogen
what cells are present during diestrus in bitches
parabasal cells, intermediate cells, neutrophils
what is the hormone profile during diestrus in bitches (estrogen and progesterone)
progesterone high, estrogen low
how do we distinguish proestrus from diestrus in bitches? what would the values be?
progesterone: high in diestrus, low/baseline in proestrus
how long is anestrus on average in bitches
4 months
what happens to progesterone during anestrus in bitches and why
drops due to luteolysis
what cells are present during anestrus in bitches
mainly parabasal
during what stage is there uterine involution in bitches
anestrus
before breeding bitches, it is important to know their ________ status
brucella canis
the reproductive exam of dogs involves (3)
1) digital exam
2) vaginoscopy
3) vaginal cytology
what are the 4 breeding methods in bitches
1) natural
2) vaginal AI (using pipette or MAVIC)
3) transcervical AI
4) surgical AI
why is it poor judgement to do surgical AI in bitches
pregnancy rates are equivalent OR superior for transcervical AI as opposed to surgical AI
what can you use fresh or fresh chilled semen for (what types of procedures)
standard vaginal AI, MAVIC, or TCAI
what can you use frozen semen for (what types of procedures)
TCAI or SAI only
to use frozen semen, what kind of testing of the bitch should be done
Witness LH test to confirm the ovulation date precisely
because dogs ovulate immature eggs, the fertile period is ______ days after ovulation (______ days after LH surge)
2-4 days after ovulation; 4-6 days after LH surge (LH surge occurs 2 days before ovulation)
T/F the more processed the semen is, the more precise AI timing should be
T
What is the gestation length in dogs from ovulation? What is this in weeks?
63 +/- 1 day from ovulation; 9 weeks
What happens to progesterone during canine pregnancy? What about if there is no pregnancy
Stays elevated regardless and falls to baseline 24-48h prior to parturition
progesterone should be higher than ___ ng/ml for pregnancy maintenance in dogs
2 ng/ml
what is the role of prolactin in canine pregnancy (2 main roles)
maintains the CL (indirectly maintains progesterone) from 35 days - term; milk production
what is the role of LH in canine pregnancy
maintains the CL
what is the role of estrogen in pregnancy
no role during majority of pregnancy; stays low until just before whelping
where does relaxin come from in canine pregnancy and why is it special
produced by the placenta; can be used to diagnose pregnancy because it is the only hormone that differs between pregnancy and non-pregnancy in dogs
what are 3 things that happen to the hematologic system during canine pregnancy
1) pregnancy-associated anemia (due to hemodilution)
2) increase in acute phase proteins
3) leukocytosis without a left shift
what are the 3 phases/periods of canine pregnancy
1) ovum (d2-17)
2) embryo (d18-35)
3) fetal (d35-birth)
what 3 processes are involved in the ovum stage of pregnancy (and what timeline are they associated with if applicable)
1) fertilization
2) embryos migrate to the uterus 10-12 days after LH surge
3) trans-uterine migration days 12-17
when does implantation of dog embryos occur and what stage is this associated with
associated with embryo stage; occurs 18-20 days post LH surge and ends 2 days later
dog organogenesis occurs during the __________ period and mineralization/ossification occurs during the __________ period
embryo; fetal
when does the canine placenta develop
20-22 days
what kind of placenta does the dog have
endotheliochorial zonary placentation
how do canine embryos get iron
at the marginal hematomas of the placenta; maternal hemoglobin is converted to uteroverdin
what are the 4 ways to diagnose canine pregnancy
1) abdominal radiographs
2) abdominal ultrasound
3) abdominal palpation
4) relaxin
abdominal palpation can be used to predict canine pregnancy between what days
25-35
what is the embryotoxicity critical time point (days post LH)
6-20
when is ultrasound performed to diagnose canine pregnancy and when does it become less accurate
d19, usually done >d24; not as good >d37
what can ultrasound be used for in canine pregnancy (4)
- gestational aging
- fetal #
- fetal viability
- fetal maturation
when is radiographs useful for canine pregnancy, what does it help us assess and when is it typically done
after d45 is when it is useful as mineralization occurs; helps us assess fetal # and size; usually done 3-5d before parturition
when is relaxin typically measured during pregnancy of dogs; when would we get a false negative and when would we see a false positive
usually measured d24-26; false negative if too early; false positive if there were resorptions/abortions
why is gestational aging important
1) bitches that need elective c-sections
2) bitches with high risk pregnancy
3) bitches that need progesterone supplementation
fetuses not viable until 2 days before pregnancy and the placenta stops supporting 2 days after whelping date
what is the gold standard for gestational aging
ultrasound <37d of pregnancy
___________ is the best way to determine due dates, but combined with _____________ it creates even more accurate predictions.
Ovulation timing; gestational aging (via U/S)
what does the ideal bitch pregnancy diet consist of
high protein, carbs, minerals, kcals; NO calcium supplementation; low in legumes; not raw
kcal: >375 kcal/cup, 400-450 kcal/cup best
what should the Ca:P ratio for bitches be
between 1:1 and 1.2:1
when should you introduce a bitch to the whelping area
5-7d before due date
when is the best time to vaccinate and to deworm a pregnant bitch
vaccinate: earlier than 2 weeks before breeding
deworm: during pregnancy as appropriate
if drugs have to be used during pregnancy, choose ___________ doses over _______ time periods
moderate; short
what category of drug should never be used during pregnancy
D (known toxic/teratogenic effects)
T/F bitches get gestational diabetes
T (rare)
early embryonic death occurs during the _____ part of pregnancy whereas abortions occur during the ______ part of pregnancy
1st; 2nd
why can dogs get gestational diabetes (2 hormones involved)
progesterone causes insulin resistance and also increases growth hormone, which is an insulin antagonist
T/F you should treat gestational diabetes with low doses of insulin in dogs
F: usually needs moderately higher doses due to the resistance
what causes pregnancy toxemia in dogs and when does it normally occur
lack of carbs or altered carb metabolism; late gestation; hypoglycemia combined with increased need for glucose causes release of fatty acids and ketones
a bitch with hypoglycemia and ketonuria without glucosuria has
pregnancy toxemia
what are 2 ways to monitor fetuses
1) Tocodynamometry (Whelp Wise)
2) Ultrasound (to monitor heartbeat)
T/F Radiographs can be used to ID fetal death
T (air in uterus, balling of fetus, deformities)
what are some signs of pseudopregnancy
weight gain, inappetance, nausea, mammary development, milk production, nurse toys
what are options for pregnancy termination (4)
- spay
- aglepristone (Alizin)
- prolactin inhibitors (cabergoline, bromocriptine)
- prostaglandins
what is aglepristone
a progesterone receptor antagonist (makes uterus think progesterone levels are low)
what is an important consideration if using a prolactin inhibitor (cabergoline, bromocriptine) for pregnancy termination
has to be given after 30 days of pregnancy
how should you use prostaglandin shots to terminate pregnancy in the bitch
with aglepristone or prolactin inhibitors as it lowers the dose and results in less side effects
what is a method of pregnancy termination in the bitch that is NOT recommended and why
estrogens; high incidence of pyometra or bone marrow suppression
If proceeding with pregnancy termination, what is important to tell the owners about:
- early in gestation
- mid gestation
- late gestation
early: likely will see no outward signs
mid: vaginal discharge, abortion (but will not see embryos/fetuses)
late: may see actual fetuses
what hormonal changes occur at parturition in bitches
increase in fetal cortisol (and maternal cortisol) increases prostaglandin production, which decreases progesterone production; prostaglandin and oxytocin cause uterine contractions
what is the Fergusson’s reflex as it pertains to parturition in dogs
increased oxytocin and prostaglandin results in uterine contractions -> causing fetal pressure against cervix -> further increases oxytocin
when progesterone drops below _____ng/ml, labor will begin in __________ hours; this drop is associated with a drop in temperature by at least ___ C
2; 12-36h; 1 degree
what are the 3 stages of dog labour
1) uterine contractions and cervical dilation
2) expulsion of the fetuses
3) passage of fetal membranes
what is the most common sign of 1st stage labour
panting (anorexia, shivering, restlessness, nesting)
what does stage 2 of canine labor invovle
Fergusson’s reflex; abdominal contractions; rupture of chorioallantois; uteroverdin
what membrane is usually covering pups at birth
allantoamnion
usually __ pup(s) every ___ mins for stage 2 delivery; it can go up to ______ hours between pups
1; 30; 3-4h
usually what occurs concurrently with stage 2
stage 3 (passage of membranes)
what is normal presentation, posture and position of fetuses
longitudinal cranial/caudal; extended head and limbs; dorsosacral
what are some risk factors for dystocia
- older bitch
- first or many litters
- breed
- weight
- litter size
what is the difference between primary and secondary uterine inertia
primary: no sign of second stage labour
secondary: passage of one or more pups has already happened but then failure to expel another puppy
what are some risk factors for dystocia
breed (brachcephalics), conformation, maternal illness
terrier breeds are predisposed to
primary uterine inertia
in both cases of uterine inertia, the uterus fails to respond to
oxytocin (no Fergusson reflex)
what are some fetal factors for dystocia
presentation/posture/position; abnormal fetal development; singleton litter (oversized fetus)
when should the owner call the vet in cases of birth ***
1) past known gestation date using ovulation timing
2) >70d since breeding date
3) no labour after temperature drop
4) >60d since cytological diestrus
5) >30 min with lots of straining and no pup
6) >15min with straining and pup in birth canal
7) >3h since last pup or weak intermittent abdominal contractions
8) lochia or uteroverdin without signs of labour
9) stage 2 > 18h
10) any maternal stress or illness
what % of dystocias need c-section
60-80%
what are the first steps to managing a dystocia
1) determine if theres actual pregnancy, cause of dystocia, maternal/fetal compromise
2) manage the client’s expectations
what are the conditions for medical management of dystocia
- bitch is healthy
- cervix dilated
- fetal size appropriate
- normal fetal HR
- no obstructive dystocia
- labor not gone on too long
in cases of medical management of dog dystocia, you can give _______ to increase the frequency of contractions or _________ to increase the strength of uterine contractions
oxytocin; calcium gluconate
besides oxytocin and calcium gluconate, what are 2 other treatments for uterine inertia
- glucose
- IV fluids
what are the units of oxytocin and calcium that should be given
Oxytocin: 0.5-2 U subq every 30 min
Calcium gluconate: 0.2 ml/kg 10% IV or 1-5 ml subq
what is the proper way to give calcium IV
SLOW and listen for arrhythmias
if using mechanical manipulation to manage dystocia what is the best approach
digital using cloth sponge and lots of lube
what are the indications for surgical management of dystocia
- low fetal hr (emergency <150 bpm)
- obstructive dystocia
- uterine inertia
- uterine rupture or torsion
- not responding to medical management
before cutting for a c-section, it is important to give the bitch (2):
- cerenia to prevent regurgitation
- pre-oxygenation
what can you give a bitch going in for c-section for pain control
butorphanol (reverse puppies with naloxone)
what are your choices for injectable anesthetics for bitches going in for c-section
alfaxalone or propofol (alfaxalone better)
are epidural or line blocks better for bitches going in for c-section
line blocks
what are the risks with a c-section spay
increased risk of hypovolemic shock and hemorrhage
what type of c-section is not recommended due to cutting off fetal blood supply and risk of hypoxia
en bloc
what do the goals of neonatal resuscitation center on
oxygen delivery and warming
how should puppies respond to neonatal resuscitation
frequent breaths, turning pink, vocalizing
T/F you can use NSAIDs in lactating bitches
F; can interfere with neonatal kidney development
what is the best post-op pain medication for c-section for bitches
tramadol
when would you recommend an elective c-section for a bitch
after 2 litters
what are signs that a fetus is ready for birth?
- mother lactating
- signs of first stage labor
- signs of fetal distress (FHR)
- kidneys similar to adult kidneys
- can distinguish all layers of the intestines
- peristalsis present
