Maternal Dystocia Flashcards
Definition of Dystocia
Prolonged spontaneous parturition OR
prolonged or severe assisted extraction
Types of dystocia
- maternal dystocia (constriction of tract, failure of expulsion)
- foetal dystocia (disproportion to dam)
- both
Definition of forced extraction
supplemented normal expulsion & coordinated w/ dam straining
abdominal contractions pull the pelvic brim in what direction? what does this do to the diameter of the pelvic inlet?
ventrally & anteriorly
increases diameter of pelvic inlet
if traction is applied to a non-straining cow, what direction does that pull the pelvic floor & calf? what does it do to the diameter of the pelvic inlet?
pulls caudally
decreases diameter of pelvic inlet
traction points for forced extraction
- above fetlock (or knee/hock)
- behind ears & btw jaws
When doing forced extraction what should you take care with?
- easy to rotate head & dislocate cervical vertebrae
- easy to trap maternal tissue btw foetus & dam
things to do prior to/during extraction
- adequate lubrication
- avoid jerky mvmts
- avoid xs force on head (stimulates stress)
- ensure presentation, position prior (position correctly PRN)
- check during delivery
- check direction of traction
- stimulate normal progression
The direction of force during extraction should be in what general shape?
arch
Why should the direction of force during extraction be arched?
if not: force transmitted to ventral abd wall of foetus & foetal pelvis is pulled forwards which may pull the hips/femoral trochanters forward too soon leading to hip-lock
Calving aids
people
pully
calving aid/jack + straight bar/Moorepark head
Natural expulsive force of cow
75 kg
Amount of traction that could be applied by 1 person?
160 kg
Amount of traction that could be applied by 2 people
250 kg
Amount of traction that can be applied by a calving jack
750 kg
amount of traction that can be applied by a calving jack used as a lever
3750 kg
Guideline for amount of traction applied per calf
5 kg of traction per kg of body weight of the calf
What is important to remember about calving jacks/aids PRIOR to EVERY use?
the quick release works!
Pelvic constriction may be due to…
- developmental abnormalities
- inadeq pelvis
- pelvic constriction due to fracture
How do you know incomplete cervical dilation has occurred in cattle?
1st stage signs of labour are prolonged but not progressing
In cattle, if the cervix is fully dilated
it is NOT palpable per vaginam
When the cervix in cattle is fully closed…
it may be possible to insert a finger into external opening only
if a mucus plug is present in cattle and the cervix is closed, this tells you…
calving has not started
A partially dilated cervix allows
fingers or a hand thru & feels like a fibrous ring
Why might incomplete cervical dilation occur in cattle?
- hormonal dysfxn or failure of cervical tissue to respond
- inadeq physical dilation - no approaching of calf
- hypocalcaemia (subclin)
- scar tissue from previous injury or calving
What is the term for incomplete cervical dilation in sheep?
Ringwomb
how do you know ringwomb is occurring in sheep?
ewe restless for long time w/ no lambs
How often does ringwomb occur?
> 30% of dystocia in sheep
When might ringwomb occur?
- twins
- hormonal disorder
- following pre-parturient prolapse of vagina
Vaginal prolapse is especially common in what animals?
Ewes & sows; but common in ruminants
What causes vaginal prolapse during pregnancy?
excess relaxation of pelvic tissues & increased interabdominal pressure
What are the 3 classifications of vaginal prolapse during pregnancy recognized in ewes
- Stage 1: protrudes when recumbent, but disappears upon standing
- Stage 2: remains visible upon standing, cervix NOT visible
- Stage 3: Cervix is visible upon protrusion of the vagina
Treatment for vaginal prolapse in stages 1 + 2
Clean, replace, retain (ewe)
Txt for vaginal prolapse for stage 3
epidural anaesthetic w/ or w/o xylazine (cow/ewe) + suture
What suture methods would you use in cattle for a vaginal prolapse?
caslicks, buhner’s purse string, Winkler’s operation
what suture methods would you use in ewes with vaginal prolapse?
Caslicks, purse string
what suture method would you use for vaginal prolapse in bitches?
farquarson’s submucous resection
incomplete relaxation of the vagina/vulva occurs in what animals?
- heifers, less in sheep
- occasionally in horses after Caslicks vulvoplasty or premature foaling
- over-fat-conditioned heifers
- interrupted parturition
- older animals after previous calving injuries
Txt of incomplete relaxation of vagina/vulva
- gentle traction
- manipulation & stretching
- episiotomy
- c-section
What is the purpose of an episiotomy?
to prevent upward tear onto the rectum (aka 3rd degree perineal laceration)
Where do you incise the vulval lips in an episiotomy?
at 10 or 3 o’clock
What are the 2 types of vaginal cytoceles?
- prolapse of the bladder thru the urethra
- protrusion of the bladder thru a rupture in the vaginal floor
Txt for a vaginal cystocele
- epidural 1st
- Prolapsed bladder thru urethra: differentiate from protruding foetal membranes, then manipulate until inversion
- protrusion thru vaginal floor rupture: invert organ thru rupture & suture
other abnormalities causing maternal dystocia
- neoplasia (rare)
- bony protrusions on the pubis
- prepartum rupture of uterus
- rupture of vagina
inguinal hernia occurs mainly in
bitch (acquired or congenital)
diaphragmatic hernia may occur in what species and uncommonly contains…
bitches; rarely contains pregnant uterus
ventral hernia is seen in
old cats & bitches w/ weak abd muscles; large animals esp cows; occasionally in mares
what species most commonly sees uterine torsion?
bovines (7-8% at parturition)
What is uterine torsion
when the uterus rotates along the long axis
the point of torsion in uterine torsion is most commonly
anterior vagina
the majority of cases of uterine torsion are in what direction
anticlockwise
The degree of torsion in uterine torsion varies between
45 and 360 degrees
txt options of uterine torsion
- (un-torse if close to parturition)
- (C-section if not progressing)
- rotate per vaginam
- laparotomy & un-torse & deliver per vaginam
- laparotomy & Caesarean
Causes of uterine torsion
- as pregnancy advances, the cranial part of the uterus moves forward & downward w/ no stabilising attachment -> if dam or foetus make a sudden mvmt the unstable uterus can rotate
Clinical signs of uterine torsion
- prolonged 1st stage of labour
- discomfort, ‘rocking horse’ stance
- lips of vagina may be pulled in
- vag exam: oblique spiral
- if torsion is <180 deg, foetus can be palpated (which can be used to untorse)
Expulsive deficiency comes in what 2 forms? what are they?
- primary uterine inertia: original deficiency in contractile potential of myometrium
- secondary uterine inertia: result of dystocia (too tired, cannot contract)
What is expulsive deficiency?
failure of abd expulsive force musculature causing incapability of contraction or too painful to contract
What signs do you see in bitches or sows during expulsive deficiency?
- nervous voluntary inhibition of labour (bitch)
- hysteria (sow)
expulsive deficiency is due to
excessive stress, pain, etc.
Causes of primary uterine inertia
- single pup/kitten syndrome: too low ACTH & cortisol to initiate parturition
- excessive overstretching of uterine muscles -> no contractions occur
primary uterine inertia in expulsive deficiencies is common in what animals?
bovine, sheep, mare, sow
Txt of primary uterine inertia expulsive deficiency
- oxytocin
- assisted delivery
- Calcium to help
- stressnil in sows
- C-section as needed
