Canine Pregnancy Flashcards
describe canine conception
- oocyte matures 2 days post ovulation
- fertilization
- oviductal transport: 9-13 d
- transuterine migration
- implantation 16-18d post ovulation
NO maternal recognition of pregnancy!
CL is the only source of progesterone during preg (secretes same amount whether pregnant or not)
describe endocrinology of canine pregnancy
- progesterone: produce by CL only increases and stays elevated for 1st half
- prolactin: produced by anterior pituitary; steady increase throughout preg
0important for CL maintenance late preg - relaxin:
-produced by placenta!
-can detect postpartum bc trophoblastic cells take a while to slough
describe canine placentation
- zonary
- placental (marginal) hematomas: uteroverdin
- pups covered in amnion, which is NOT fused to chorioallantois
- endothelial placentation: 5-10% IgG transfer
what does green discharge mean?
placental separation of at least one pup, NEED TO see a vet!! an emergency!
describe pregnancy diagnosis options
- transabdominal palpation
- relaxin
- ultrasound
-B mode
-doppler - radiographs
NOT PROGESTERONE!!!! will be same regardless of preg
describe advantages and disadvantages of transabdominal palpation
advantage:
-cheap
-no equipment needed
-2cm swelling by d30
disadvantage:
-small window accuracy (30-45d and >45d)
-inaccurate (tense abdomen, obese or a large singleton pup)
-iatrogenic fetal death
gie pros and cons of transabdominal ultrasound
pros
1. early diagnosis: vesicles 18-20d, heartbeat at 25d
- late preg: fetal viability and maturity
-HR should decrease as progress until AT parturition
-peristalsis/GI definition is last thing to mature! if see, feel confident will survive C-section
-renal development (once see cortex and medulla = almost to term) - can assess: fetal viability and stress, age, placental disease, fetal maturation
cons:
-puppy counts not 100% accurate due to miscounts and resorptions
-tell owner +/- 1-2 puppies
describe abdominal radiographs for pregnancy detection
- only useful for later gestation when mineralization:
>45d in dog and >38d in cat - assess: gestational age, fetal death (gas, disarticulated skeleton), feto-maternal disproportion
- best method for puppy count
tips:
-take at approx 55-60d for easier images
-have dog defecate first
-or don’t feed dog that am
describe relaxin as a method for pregnancy detection
- can get false negatives <28d gestation
- can get false + after abortion or whelping
- NOT an assessment of fetal health or fetal number
describe care of the pregnant dog (6)
- all vx PRIOR to breeding
- good nutrition and moderate exercise
- isolate the last 3 weeks of preg (no exposure to infectious diseases)
- introduce whelping box last week of preg
- high risk pregnancies: weekly ultrasound and progesterone monitoring
-don’t give progesterone before 30d!!! use altrenogest is Ellerbrock rec - be careful with females naive to CHV-1
describe feeding a pregnant dog
don’t need to feed them more!
just feed maintenance requirements up until 6 weeks prior to gestation then switch mom to puppy food
describe exercise during pregnancy
- maintain activity level
- maintain weight
- avoid heat stress!
describe prediction of whelping
- lactate up to 2 weeks pre-whelping: not super useful
- nesting 1 week pre-whelping
- breeding timing:
-65 +/- 1 day from LH peak
-63 +/- 1 day from ovulation
-57 +/- 2 days from D1 diestrus
-55-72 days from last breeding - fetal maturity:
-radiographs: start with axial skeleton and then work prox to distal on limbs for mineralization; so look for mineralization of teeth- mineralize last! (but in last 3-8 days so still wide window)
-ultrasound: GI development, renal development - progesterone: drops below 2ng/ml within 24-48 hr of gestation
- rectal temp:
-take 2-3 times per day CONSISTENTLY starting with approx 55-58d gestation
-when temp <99 or drops 1.6 degrees, will whelp within 8-24 hours
-this is bc progesterone is thermogenic; when progesterone drops, body temp goes down too
describe endocrinology of parturition
- maturation of fetus adrenal cortex - fetal stress and release of cortisol
- fetal cortisol increase mom PGF2a which causes:
-increased uterine contractions on its own
-increased oxytocin = increased uterine contractions
-decreased progesterone, which increases uterine contraction and drops body temp - all of this results in parturition
may not happen with singleton puppies (not enough cortisol to trigger, often result in C section)
describe stage 1 labor in dogs
- 6-12 hours (up to 24 hours depending on owner interpretation)
- uterine contractions
- pelvic ligament and cervical relaxation
- placental separation: can see green to black vulvar discahrge
- signs: obsessive nesting, anorexia, restlessness, panting, shivering
describe stage 2 and 3 of labor in dogs
- fetal and placental expulsion
- 30-60min between pups, complete within 6 hours
- fetal membranes should pass with pups or within 5-15 min
- lochia (uterine discharge) normal up to 3 weeks post partum
- uterine involution takes up to 3 months
describe normal fetal presentation of puppies
front or back both normal!
anterior or posterior longitudinal, dorso-sacral, extended posture
describe dystocia in canines
- approx 5% incidence
-breed disposition: brachycephalic - due to
-primary uterine inertia
-feto-maternal disproportion
-singletons
-maternal abnormalities: vaginal strictures, pelvic fractures, neoplasia
-secondary uterine intertia (large litter - presentation:
-failure to initiate parturition (prolonged gestation)
-failure to progress to stage 2
-maternal illness: hypocalcemia, septicemia (esp after fetal death), colic
describe primary uterine inertia
- lack of uterine contractions
- causes:
-small or large litter
-singleton
-genetic (terriers)
-systemic diseases
-hypocalcemia
-uterine torsion
-nutrition - treatment: C-section if at term
how to define prolonged gestation?
- > 24 hours from true temperature drop
- > 2 hours from placental separation
other reference points from breeding timing, ensure everyone on same page about reference point!!
when safe to C section?
progesterone should be less than 2ng/dl AND dog should be at least 63 days post LH peak!!!
if need to perform surgery and any questions about maturity, sometimes use steroid to help hasten fetal maturation (not sure if works but worth a shot)
describe evaluation of dystocia to see if need to C section
- determine cause, or if there is dystocia
- determine if maternal or fetal compromise
- obstetrical exam:
-history
-physical exam
-vaginal exam: feel for pups or fetal membranes in caudal vagina; will not feel cervix! vaginal canal is too long
-abdominal ultrasound to determine fetal stress (<160bpm) (mild stress associated with maturity <180bpm; normal a few days out from parturition 220-250/260)
-radiographs to determine fetal number and size
what qualifies as failure to progress normally?
- > 4 hours without straining and no first puppy
- > 2 hours between pups without straining
- > 30 min between puppies with straining
- partial delivery of a puppy
- hemorrhagic or vulvar discharge
describe correction of dystocia
- vaginal manipulation
-ferguson’s reflex: put pressure on vaginal wall to activate pressure sensors to cause oxytocin release and induce uterine contractions - medical treatment
-if good maternal condition, dilated cervix, normal puppy size, no obstruction, no fetal stress and owner is okay with risks
-give oxytocin, repeat NO MORE than once without producing a puppy (not too much, want productive contractions not crazy squeeze)
- +/- calcium gluconate along with oxytocin = stronger uterine contractions when together - surgical treatment: up to 75% of cases
