Parturition and Obstetrics Flashcards
what are 5 options for pregnancy termination
-keep pregnancy and have litter
-spay
-aglepristone (alizin); only available through emergency drug release
-prolactin inhibitors; needs to be given after 30 days of pregnancy
-prostaglandins; causes luteolysis
how do prolactin inhibitors work
prolactin is luteotropic (supports CLs) -> tx causes luteolysis -> progesterone levels decrease -> termination of pregnancy
two names of prolactin inhibitors
cabergoline, bromocriptine
how does aglepristone work
progesterone receptor antagonist, tricks uterus into thinking progesterone levels are low
what do you need to be aware of if using prostaglandins to terminate pregnancy (how many injections, side effects)
-multiple injections needed
-side effects; hypersalivation, vomiting, diarrhea, micturition, panting, tachycardia (affects all smooth muscles)
what are prostaglandins used in combination with and why
with algepristone or prolactin inhibitors. allows for lower doses and therefore less side effecs
if used alone its very hard on the bitch
why is a mismate shot not recommended as pregnancy termination
high incidence of pyometra following treatment, bone marrow suppression also possible. never use it!
what can you expect to see if there is pregnancy termination during early, mid and late gestation
-early; could see no outward signs of pregnancy termination (resorptions)
-mid gestation could see vaginal discharge; abortion (embryos/fetuses too small to see)
-late; could see actual fetuses; more difficult for clients to see this so it should be terminated before this point if possible
what can you expect when P4 drops below 2ng/mL
labour beings in 12-36 hours
what happens when P4 drops temperature wise
temperature…. drop by at least 1C to expect parturition
what is the most common clinical sign of first stage labour
panting! sometimes its the only clinical sign present
what happens during phase 1 of labour? how long does it last?
-synchronous uterine contractions; not visible from the outside
-cervical relaxation
-typically lassts 6-12 hours but can last up to 36 hours in primiparous bitches
clinical signs during stage 1 of laboour
◦ Anorexia
◦ Panting
◦ Shivering
◦ Restlessness
◦ Nesting
◦ Refusing to eat
steps in fergussons reflex
◦ Fetus in birth canal → stretching cervix, vagina, uterus → oxytocin release
what happens during stage 2 of labour
◦ Expulsion of fetuses
◦ Fergusson’s Reflex
◦ Visible abdominal contractions
◦ Allantochorion ruptures often during birth
what often ruptures during birth (stage 2)
◦ Allantochorion ruptures often during birth
what often covers pups at birth
◦ Allantoamnion often still covers pup at birth
what is uteroverdin
◦ Breakdown product of biliverdin from placental margins
what is normal timing for the entirety of parturition, and time between pups
◦ Usually 1 pup every 30 mins – 1 hr
◦ Can go up to 3-4 hrs between pups in some cases*
◦ Usually have all pups born within 6hrs but can go up to 24hrs in large litters
what happens during stage 3 and when does it occur
◦ Passage of fetal membranes
◦ Occurs concurrently with stage 2
how long should stage 3 take
◦ Can be passed with the puppy, or 5-15 mins after the pups
◦ Can have 2 pups before 1 placenta
are retained placentas common in dogs
no they are rare
what is presentation relating to and what is normal in dogs
◦ Relationship of spinal axis of the fetus to that of the dam
◦ Longitudinal vs transverse
◦ Longitudinal cranial/caudal = normal
what is posture relating to and what is normal in dogs
◦ Relationship of the fetal extremities or the head/neck to the body of the fetus
◦ Extended head and limbs = normal
what is position relating to and what is normal in dogs
◦ Relationship of the dorsum of the fetus in a longitudinal presentation, or the head of the fetus in a transverse presentation to the quadrants of the maternal pelvis
◦ Dorsosacral = normal
risk factors for dystocia (5)
◦ Age of bitch (>6 years = associated with greater risk; especially if 1st litter)
◦ Parity (how many litters the bitch has had)
◦ Bitch breed
◦ Bitch weight
◦ Litter size
is dystocia due to materal or fetal factors
can be due to either!
what doesnt occur in cases of interia
no fergusson reflex occurs bc uterus fails to respond to oxytocin
what happens with primary uterine inertia
◦ No sign of 2nd stage labor – never have delivery of a puppy
◦ Partial primary inertia = contractions start and stop without passage of a puppy
◦ Partial dilation of the cervix
what are some causes of primary uterine inertia (4)
◦ Genetic (terrier breeds)
◦ Large litter – stretching of the
uterus
◦ Inadequate stretching with 1-2 pup litters
◦ Hypocalcemia + other signs of systemic illness
what happens with secondary uterine inertia
◦ Passage of 1 or more pups
◦ Prolonged uterine contractions fail to expel a pup
what are some causes of secondary uterine inertia (3)
◦ Can occur for similar reasons as primary uterine inertia
◦ Can occur in large litters
◦ Can occur if a fetus is obstructing pelvic canal
