36, 37, 38 - dystocia Flashcards
what is eutocia?
normal birth
what is dystocia?
abnormal birth
- inadequate progress during birth
- failure to give birth w/o assisstance
what are 3 locations of origin of maternal caused dystocia?
uterine
abdominal
pelvic
in the pelvis of the FM, the cause of dystocia may be ____ or _______ in nature
bony
soft tissue
what are 4 causes of fetal causes of dystocia?
- disproportionate size
- mal disposition / mis orientation
- failure to initiate birth
- death
t/f
bitches whelp 65 days posts breeding date
false
65 days post LH surge, regardless of breeding time
what info must be known about the situation before proceeding with the dystocia?
age parity breed sire due date prior exams / interventions define presenting complaint relative value of dam vs neonate - which does client want to preserve / which is able to be preserved
components of clinical exam in dystocia case?
strength and health of dam
intensity of contraction
is she ambulatory?
metabolic derangements - energy, minerals, hydration
in what species are metabolic derangements particularly important to consider at time of parturition?
dairy cattle
dogs
small ruminants
what to assess in birth canal quickly?
patency trauma fetal body parts / obstruction fetal membranes fetus alive? viable? force of abdominal contractions? Ferguson's reflex?
why is it important to evaluate if the allantocorion has ruptured yet?
b/c if not, then she may just be in first stage of parturition
what does viable mean?
able to survive / live
t/f
viable is the same things as alive
false
what does alive mean?
currently living
what is Ferguson’s reflex?
stimulation of vagina - stimulates oxy secretion so contraction are stimulated
how can the fetus/es be evaluated?
trans rectal plapation
u/s
vaginal exam
x ray
how to establish if fetus is alive if in the cranial presentation?
- interdigital reflex
- suckling reflex
- eye reflex (press on eye ball)
which fetal reflex disappears first?
which remains positive in hypoxic calves?
interdigital reflex disappears 1st
eye reflex remains
what reflexes to establish fetus is alive in the caudal position?
anal reflex
umbilical artery pulse
femoral artery pulse
what is the conclusive diagnostic to determine if fetus is alive?
u/s
after the exam, what should you know?
obstructive or non obstructive dystocia strength of dam status of birth canal exact orientation of fetus in birth canal fetus alive or dead fetus viable? relative value of dam and fetus to client prognosis for survival / future breeding
5 methods a dystocia may be resolved?
vaginal delivery w traction vaginal delivery after fetal mutation vaginal delivery with fetotomy cesarean section no Tx - sacrifice
what are 3 types of c sections?
survival
terminal
hysterotomy OR ovariohysterectomy
how to distinghush an obstructive vs a non obstructive dystocia?
obstructive has good contractions and non obstructive has poor contractions
despite good contractions, what are 3 other issues commonly present with obstructive dystocias?
usually abnormal orientation
often dead fetus
feto-maternal diss proportion
what is the typical orientation, living status and space status of fetus/es during a non obstructive dystocia?
all good
usually normal orientation
often alive fetus
usually enough space
t/f
uterine torsions often resolve on their own so should be monitored but nothing done right away
false
always try to correct a uterine toresion
4 methods to resolve an obstructive dystocia?
- that is NOT a uterine torsion
mutation
traction - lubrication
fetotomy
c section
t/f
ecbolics are good therapies to assist with obstructive dystocia?
false
what are 2 examples of ecbolic therapy?
Ca
oxytocin (oxy)
proper way to apply traction on fetus?
roll fetus into dorso ileal position and then apply alternating traction on hind limbs
stagger legs so shoulders are staggered
what is MC used for epidural anesthesia?
drug
amt
dose
5-8 mL of 2% lidocaine
what does myometrial relaxation require?
- removal of oxytocin (can occur thru Cd epidural anesthesia)
- competitive antagonist (B2 agonist)
what is the legal option for a competitive B2 agnoist in the US?
what is a draw back?
adrenalin
short acting
what is the best way to mutate a calf to reduce the risk of tearing the already taught uterine wall?
- create space in front of the pelvic inlet to allow for un-flexion of the leg
- keep the joint to the uterine wall and the foot to the calf
t/f
mandible snares are a good way to provide traction for a calf or foal in dystocia
false
mandible is only used to guide the head - NO traction on the fetus head
what must be achieved during mutation of a fetus?
- convert shoulder flexion into carpal flexion
- in Cd presentation: convert hip flexion into hock flexion
what is fetotomy?
dis memberment of fetus that is dead w/in the birth canal
what supportive therapy must be provided to dam during fetotomy?
at what point in the procedure?
fluids, NSAIDs, sedation, pain control, abx maybe
initiate prior to the fetotomy => b/c uterus full of endotoxins that you will stir up and she will absorb a lot rapidly so will become critically ill
when making selected cuts during a fetotomy, each cut MUST achieve improved chances for delivery.
in what 3 ways might this occur?
- remove flexed body part that cannot be extended
- dec diameter of fetus [at level of shoulder primarily]
- create more room to work inside the birth canal [removing head]
t/f
when performing a fetotomy, use short and fast strokes of the wire the maximize effect
false
use longest possible strokes and highest possible friction
if using a small area only, the wire will get very hot and will fatigue/weaken
after the fetotomy, what is critical to do?
when doing this, why is sterility not a huge issue?
flush the uterus
the uterus is already full of bacT, just clean it out well with a good clean source of water
2 benefits to flushing uterus after fetotomy?
flush out bacT
flush out “soup” of materials/fluids that bacT will love to grow in
what is a laparohysterotomy?
cesarean section
what is common location on lateral side of cow for c section incision?
ventral incision?
fold of skin hanging from the tuber coxae and down over the costal arch
ventral: over milk vein in longitudinal direction
what fetal structure is important to identify first in C section if fetus is in the Cr position?
Cd position?
cr position: hind limb
cd position: front limb
when incising the uterus, what structures are important to avoid?
placentomes
how far should the incision in the uterus extend from?
the length of the lower hind limb -> from fetlock to calcaneous
why must the uterus NOT slip back into the abdomen?
risk spilling uterine contents into the abdomen - causing peritonitis - compromise well being of dam
what type of suture material used in uterine wall?
dissolvable
often PDS
t/f
when closing the uterus, a suture pattern that penetrates the full thickness of uterine tissue and enters the lumen is necessary for a secure closure.
false
if suture penetrates the lumen, it will dissolve to quickly and may lead to suture failure
why should mattress patterns such as cushing be avoided when closing the uterus?
b/c they occlude blood supply to wound edges and delay wound healing
what are characteristics of the Utrecht uterine closure pattern?
begin distal to dorsal comissure of incision, in healthy tissue, and end ventral to comissure of incision
make bites far to near EVERY TIME
bury knots but NOT in uterine lumen
zig zag fashion at about 45* angle to incision
benefits to Utrecht closure?
immediate tight seal - NO leakage thru incision
no suture material on serosal surface so no omental adherance should occur so no adhesions [catch: there actually is suture exposed]
what is not perfect about the Utrecht pattern?
why the modified pattern is preferred by many?
suture far to near and the near to far - 4 holes in a row
so near hole pulled to near hole and far hole pulled to far hole
no suture material on serosal surface
why might emphysema occur after c section?
what is done to px this?
b/c there is huge void in abdomen where calf used to be, now filled with air
express the air out of the peritoneal cavity before taking the last bite when suturing
t/f
cows often experience temporary and reversible nerve damage after c sections
true
give her time and good footing to recover at her own pace
what is first thing to determine if uterine inertia is suspected?
is the dam actually in labor
after it is determined that the dam is in labor and uterine inertia is happening, what should we determine next?
is the inertia 1* or 2*?
what are some causes of uterine intertia?
lack of stretching of cervix or anterior vagina
over distended uterus
metabolic disorder
exhaustion or excessive intervention
3 MC causes of bovine dystocia
feto maternal disproportion
abnormal posture
abnormal presentation
t/f
it is appropriate to deliver a dead calf by c section
false
do NOT deliver dead calf by c section
most diary cattle - 92% - will not produce milk and will leave the farm as a result if this occurs
if calf alive at time of c section, 87% chance cow will do fine
what is schistosomus reflexus?
congenital cleft of the trunk; limbs are mal formed and ankylosed
spine lacks some vertebra, and often entire sacrum
what is perosomus elumbis?
flattened and deformed pelvis, hindlimbs ankylosed
what is tibial hemimelia (TH)?
what breed?
recessive genetic defect traced to short horn bull in 1970s
calves have many congenital defects: absence of tibia, twisted legs/absent or deformed bones, abdominal hernias, cryptorchid, meningocele
what is PHA?
pulmonary hypoplasia w anasarca
recessive genetic, cattle
calves have poorly formed lungs and excessive subQ edema
lethal!
what is arthrogryposis multiplex?
curly calf syndrome
bovine, hereditary - lethal autosomal in angus
muscle hypoplasia, arthrogryposis and kyphoscoliosis
what is arthrogryphosis?
flexed joint d/t muscle contraction
what is kyphoscoliosis?
ventral and lateral curve of spine
there are 3 genes affected in arthrogryposis multi plex. what is 1 related to?
1 gene involved in neuromuscular junction
how does arthrogryposis multiplex affect dam / birth process?
results in lack of fetal movement in utero
the foal has very long fetal extremities. why is this significant?
mare has a higher risk of uterine tears occurring during mutation
how rapidly can the foal die and how quickly is the mare’s life in danger during dystocia
foal: 30-60 mins
mare: 3 hours
how much space is needed in front of the pelvis to rotate the limb to fix the flexed carpus?
18 inches
must retropulse foal back into the mare before mutating
how long do cows have when dealing with a dysticoa typically?
mares?
cow: 24 hours
mare: emergency!
what are 4 basic and initial measures to take when dealing with mare dystocia?
walk her
epidural anesthesia
pass endo tracheal tube
heavy sedation
during mare dysticia, what cavity should you always work inside of?
allantoic cavity
*outside of the uterine lumen
where should the muzzle of the foal be located during normal birth?
at the mid level of the cannon bone
what is the best position for the mare to be in during fetal mutation?
on her back with her legs hoisted high into the air
while she is anesthetized
what supportive care should you provide to the mare during dystocia?
fluids
NSAIDs
heavy sedation
broad spectrum abx
what abx are best used for a mare during dystocia?
gentamicin and penicillin
after the dystocia, what care does the mare require?
fluids flush out uterus 5 L mineral oil to Px impactions prophylactic care for laminitis continued abx therapy dry cow mastitis prep to Px vaginal mucosal adhesions
what is #1 complication after mare dystocia?
infection
what occurs during a red bag delivery in a mare?
premature placental separation
failure of the cervical star to rupture
normally, when should the cervical star rupture?
what causes it to rupture?
with inc uterine pressure at the initiation of labor
if placental separation has occurred, what else has also occurred?
fetal death - b/c fetus loses placental support
what is the first thing to do during red bag delivery?
cut open the red bag - get the foal out b/c it is dying
what are 2 MC causes of red bag in mares?
fescue toxicosis
partus induction
what tissue layer is the “red bag” ?
allanto chorion
what structure does not mature properly, whether d/t natural problem or iatrogenic problem, which may result in red bad delivery?
cervical star fails to mature properly
what is common problem with foals born in a red bag delivery?
hypoxia
o2 deprived neonate -> neonatal mal adjustment
also: neonatal septicemia
what are common reasons for dystocia in small ruminants?
postural abnormallities of twins or triplets
oversized single fetus
“ring womb” = idiopathic failure of cervix to dilate
t/f
in sheep and goats, the neonate can be delivered in unilateral shoulder flexion to allow passage of the relatively large head of the fetus
true
how is a ring womb resolved in small rumintants?
c section
t/f
it is appropriate to use a head snare to help deliver small ruminant fetuses.
true
what type of anesthesia is used in small ruminant c section?
local infiltration along incision line
mild sedation and hold animal in recumbent position
where is the incision for c section made in small ruminants?
L or R flank
ventral midline
groin in front of udder - where the skin is bare
what are characteristics of alpaca fetuses?
very long extremities and necks
bilaterally flexed limbs
t/f
hembras do not tolerate c section surgery well
false
they tolerate it very well
what are MC causes of canine dystocia?
uterine inertia [hypocalcemia, stretching]
feto maternal disproportion
single pup syndrome
excessive attention leading to distraction of bitch during birth
t/f
traction, mutation and fetotomy are commonly practiced on bitches
false
these methods are impractical
what is the common Tx for canine dystocia?
c section
what ecbolics are used in canine dystocia?
Ca
oxytocin
what is an anasaca puppy?
pup born with excessive fluid accumulation of fluid under the head and in the abdomen
what is 1* source of circulating Ca levels?
what is another source?
GIT
skeleton may be accessed
what hormone induces mobilization of Ca from skeleton?
PTH - parathyroid hormone
Most Ca in circulation is bound to protein or ionized?
therefore, is it readily available or not?
bound to protein
bound so NOT readily available
what governs the amount of Ca available in ionized form?
pH of blood
what is the effect of high pH on ionized Ca levels?
high pH => Ca goes into bound form => less Ca readily available
how does the temperature of a bitch’s whelping environment affect her Ca availability?
if kept in a warm area, she will get hot and pant -> inc pH in blood -> more bound Ca -> less ionized Ca
t/f
when bitches whelp in a hot environment, their total Ca is lower than bitches given a cooler area to whelp
false
ionized Ca is lower => total Ca is the same
what, specifically, is hypocalcemia a deficiency of?
inadequate circulating free Ca
why is Ca from the GIT limited for bitch on the day of labor?
- highest demand for fetal skeletal development on this day
- initiation of lactation
- reduced feed intake
t/f
prior to parturition the bitch should be kept on a high calcium diet.
why or why not?
false
lower calcium diet - or at least NOT given excessive Ca
if Ca levels are high, the PTH will not be active and will take a few days to adjust to her higher demans
if Ca levels are lower, the PTH will already be active and mobilizing Ca for the bitch at the time of parturition
when should Ca be supplemented for bitch?
after parturition
how to Px hypocalcemia in bitch during parturition?
feed maintenance levels of Ca during pregnancy
px overheating during whelping
how to tell if canine fetus is alive vs viable?
best test to determine this?
normal / alive = 200 bpm
u/s exam
what is heart rate of compromised canine fetus?
and a critical fetus?
150-200 bpm
how to assess patency of birth canal in bitch?
digital or vaginoscopic exam
how to assess the litter size in canine?
x rays
t/f
obstructive dystocias are best resolved with ecbolic therapy
false
NO ecbolic therapy
c section is MC resolution
tx of uterine inertia?
5% dextrose and hydration
calcium (give to effect)
oxytocin (use small doses frequently)
how much oxytocin may be given total to a bitch?
when should it be given?
1-5 IU total dose
give oxy AFTER Ca
t/f
a common cause of uterine inertia is oxytocin deficiency in bitch
false
deficiency of oxytocin is uncommon => MC is a deficiency of Ca
one method of administering Ca to a whelping bitch is to measure her ionized Ca levels in her blood, calculate her deficiency and then give her the appropriate amount.
a less precise method but effective and much more practical is what?
listen to her heart rate - a hypocalcemic heart rate will have a tremor and a fast, shallow pulse
deliver a bolus of .5 mL of Ca and listen for a slowed heart rate
continue giving her boluses of Ca until her heart rate stabilizes and remains slower
at what point should fetal membranes be removed in canine c section?
how should they be removed? why?
after last pup is out
remove them slowly to avoid consumption coagulopathy
during a c section in a bitch, when should oxy be given?
after the fetuses are delivered
what induction drug should be used during canine c section?
propofol
lidocaine locally
why should poly ionic fluids be given to a bitch during a c section?
b/c once the pregnant uterus is removed, the abdominal pressure will plummet -> blood may flow into the organs -> leading to a huge drop in blood pressure
benefits to a lumbo sacral epidural anesthetic for bitch during c section?
pain in bitch is controlled
bitch is not anesthetized
no risk to viability of puppies d/t anesthesia
when are elective c sections performed in the bitch?
what MUST BE KNOWN in order to plan for an elective c section?
last day or 2 of gestation
MUST KNOW the day of the LH surge
if the date of the LH surge is not known, what can be measured and used as indicators of the end of gestation?
core temperature falls
p4 levels reach baseline
what can be used to accelerate fetal maturation?
dexamethasone
what dictates the size of the pup?
placental support
why does a singleton pup fail to initiate labor?
its adrenal function does not provide enough of a signal to the bitch to trigger labor
if the LH surge date is not known and the bitch is carrying a single pup, how is the date of c section selected?
x ray - look for teeth and toe calcification
or intestinal bowl movement if high resolution u/s
why aren’t temperature drop or serum p4 used in case of singleton pup to determine stage of gestation?
b/c they do not occur -> these signals require a trigger from the fetus, which does not occur
why might rubbing a bitch’s belly help her during parturition?
deep abdominal massage will stimulate smooth muscle contraction
if last pup was born 2 hours ago, what can be done to help the bitch?
deep massage to her abdomen
walk her
stimulate vagina digitally
small oxy dose
