Obstetrics Flashcards
What is the first step to successful delivery assistance? What should producers/owners do?
recognizing a normal delivery
triage pregnant animals
What triggers the beginning of parturition?
uterine crowding causes increased fetal ACTH, which initiates a cascade of hormonal changes
- fetus decides the date, dam decides the time
- larger litter = more crowding = shorter gestation
- singleton/mummy = no crowding = will not initiate parturition
What are the 3 stages of parturition?
- preparatory - uterine contraction, rotted fetal position (equine), chorioallantois/chorioamnios rupture
- fetus enters the vagina and is expulsed
- expulsion of fetal membrane
What is Ferguson’s reflex?
neuroendocrine reflex caused by the straining forces of the fetus against the cervix and cranial vaginal, inducing the release of additional oxytocin
What tends to increase the risk of a foal failing to survive during parturition?
every 10-minute increase in duration of labor at stage 2 beyond 30 mins
Parturition, differences in species:
In what 2 situations should intervention during parturition in mares be done?
- premature placental separation (red bag)
- foal not born within 20 mins after a mare releases allantoic fluid
In what 3 situations should intervention during parturition in cows be done?
- non-progressing parturition stage 1 (uterine torsion)
- > 2 hr after the first appearance of the amnion at the vulva
- no progress observed within a 30 min interval
In what 3 situations should intervention during parturition in bitches/queens be done? In bitches especially?
- no delivery of pup/kitten within 4 hours after the beginning of stage 2
- exhibit strong contraction for >30 mins without producing pup/kitten
- prolonged intercal (>2 hr) between delivery of pup/kitten
green vaginal discharge without delivering the first pup - obstructive dystocia, C-section recommended
In what 2 situations should intervention during parturition in small ruminants be done?
- fetal membranes at vulva for >3 hr without delivery - digital examination shows an incompletely dilated cervix (ringworm) –> C-section, dilation not helpful
- 30 min rule - examine 30 mins after the breaking of the chorioallantoic membrane and after delivery to look for an additional fetus
In what situation should intervention during parturition in camelids be done?
cria not born within 20 mins after the beginning of stage 2
- like mare, has a short stage 2
In what situations should intervention during parturition in sows be done?
piglet interval >2 hrs
What is the difference between superfecundation and superfetation?
successive fertilization of two or more ova by different sires –> more common in feral situations and in swine
successive fertilization of 2 or more ova of different ovulations, resulting in presence of embryos of unlike ages
What is the difference between ecbolic and tocolytic agents?
increase uterine contractions (PGF2a, oxytocin)
inhibit uterine contractions
- N-Butylscopolammonium (Buscopan) - anticholinergic
- Clenbuterol - anticholinergic
- epidural anesthesia
How is fetal disposition described?
- Presentation
- Position
- Posture
What is fetal presentation? What are the 3 terms used to describe it?
orientation of the fetal spinal axis to that of the dam and the portion of the fetus that enters the vaginal canal first
- LONGITUDINAL - anterior vs posterior, fetal spine parallel to dam’s
- TRANSVERSE - ventral vs dorsal, fetal spine not in like with dam’s
- VERTICAL - ventral vs dorsal, fetal spine is perpendicular to dam’s (dogsitting)
How is fetal position described?
LONGITUDINAL - based on the surface of the maternal birth canal to which the fetal vertebral column is applied OR the relationship of the fetal dorsum to the quadrant of the dam –> dorsal (dorso-sacral), ventral (dorso-pubic), left/right lateral (left/right dorso-ilial)
TRANSVERSE - relationship of the fetal head to the quadrants of the dam –> right/left cephalo-ilial
What is fetal posture?
disposition of the movable appendages of the fetus, involving flexion or extension of the neck or limb joints
- lateral flexion of the neck
- hock flexion
Fetal presentation, position, and posture:
What are 4 possible methods of obstetric manipulation to aid parturition?
- REPULSION - fetus repelled from the pelvic canal to increase space in the uterus to correct malposition
- MUTATION - manipulation of extremities with correction of postural abnormalities
- ROTATION - turning fetus on its longitudinal axis (hip-lock during calving)
- VERSION - manual changing of the polarity of the fetus with reference to the mother to correct transverse presentation –> head and forelimbs are repelled into the uterus while the hindquarters are pulled into the pelvic canal
What are 7 causes of dystocia?
- fetal materal disproportion
- faulty fetal disposition
- hereditary - schistosomus reflexus, hydrocephalus, anasarca
- nutritional - obesity (pelvic canal obstructed by fat
- infectious - dead fetus
- traumatic - hernia, rupture of prepubic tendon, tear of abdominal muscles
- uterine inertia
Causes of dystocia:
How are small animal dystocias most commonly resolved? What other method are commonly used in large animals?
medical
- mutation and rotation
- forced extraction
- fetotomy
- C-section
What restraints are recommended for assisted vaginal delivery and controlled vaginal delivery?
minimal - light sedation, epidural anesthesia, NEVER deal with it in a chute
general anesthesia