Therio - Bovine - Obstetrics & Dystocia 1

drraythe's version from 2017-09-10 02:30


Question Answer
Abnormal birth is calledDystocia
Normal birth is calledEutocia
What are the 3 kinds of dystocia?(1) 1° Inertia
(2) Obstructive Dystocia
(3) 2° Inertia
Explain dystocia due to 1° inertiaForces that propel the fetus are absent
Explain obstructive dystociaForces that propel fetus are normal, but no progress of fetus through birth canal
Explain dystocia due to 2° inertiaConsidered a complication of obstructive dystocia due to exhaustion of myometrium
What are some reasons there might be a dystocia due to 1° inertia?(Forces that propel the fetus are absent) #1 cz is metabolic disturbances, esp Hypocalcemia!! However, can also be from Over/undernutrition, Fetal malformation (monsters), Uterine torsion, Uterine rupture, pain, or debility.
What are the main czs of Obstructive Dystocia?(1) Feto-materal disproportion: small heifers, large sires, bull calves, over or under nutrition
(2) Faulty fetal disposition
(3) Multiple fetuses
4) Failure of soft tissue dilation (damaged cervix, unstretched vulva of heifer)
(5) Fetal malformation (monsters) [[dont forget that obstructive leads to exhaustion, hence 2° inertia]]
MOST COMMON czs of dystocia she says areFeto-maternal disproportion & Faulty fetal disposition, we well as Incomplete dilation of cervix + vagina, twins, Fetal malformations (monsters), Uterine inertia, Uterine torsion
List some Metabolic disturbances which can cz a 1° inertia uterine dystociaHypocalcaemia
How it is that Fetal malformation (monsters) can cz dystocia?Either does not initiate partus (1° inertia) or malformation results in dystocia (obstructive dystocia)
Hypocalcemia would cz what kind of dystocia?1° inertia
CSs of hypocalcaemia?Recumbent, Torticollis (head flexed so it looks like she’s looking at her flank)
If a cow is having dystocia due to Hypocalcemia, what other body system should you be concerned about?The RUMEN-- need Ca for GI, Hypocalcemia can cz BLOAT
If you see a recumbent cow at term looking a bit bloated w/o myometrial contractions, you think..Subclinical Hypocalcemia
What might be some czs for fetal malformations which would cz dystocia?Viral Infxn
Plant teratogens
What are some viral Infxns in utero which can cz fetal malformations?BVD
Rift Valley Fever
What are some Plant teratogens that can cz fetal malformations?Lupines
Poison Hemlock
Tree tobacco
What are some congenital fetal malformations?Bulldog calves in Dexters & Herefords
Examples of Different malformations of the fetusHydrocephalus
Schistosomus reflexus
Contorted joints (arthrogryposis, torticollis, kyphosis, scoliosis, lordosis = “Crooked calf syndrome”)
Fetal ascites
Fetal anasarca
Chondrodystrophia fetalis
Muscular hypertrophy
Perosomus elumbis
Amorphus globosus
What is Perosomus elumbis?Partial or complete agenesis of the lumbar, sacral, & coccygeal area & accompanied by posterior bimelic arthrogryposis characterized by ankylosis of joints w/ associated malformations of the musculature.
What is a Bulldog calf?Calf suffering from Dwarfism/chondrodysplasia
What is Schistosoma Reflexa?Schistosomus reflexus occurs very early in embryological development. The abnormality is associated w/ severe developmental anomalies of the spinal column & consequent failure of the abdominal wall to close. The spine is bent dorsally so that the head & tail curve towards each other & the fetal viscera are free floating in the amnion.
What is Amorphus globosus?Instead of a typically developing fetus occurs thereby to form 1 of hairy skin covered, more or less spherical structure, the shares of all 3 germ layers contains; the differentiation of its contents can vary greatly. Amorphus globosus is lack of fxnl organs not viable
Where does uterine rupture usually occur?Along the major curvature just cranial to cervix
What are some of the main czs of uterine rupture?Pre-existing weakness of the uterine wall, Following ischemia due to uterine torsion/breech position, Large emphysematous or dropsical calves, Prolonged partus, dry birth canal, iatrogenic
How do you treat uterine rupture (how does Tx vary?)(1) If less than the width of a hand, then Repair may not be necessary if small & dorsal due to rapid uterine involution, so just do Repeated Oxytocin Injxns + 7-10 days of ABx
(2) If bigger than the width of a hand, then Often dystocia required C-section to repair uterus. Need to do 1 handed “Blind” suture closure, or you need to Prolapse uterus & repair (Using 10ml epinephrine in 250ml saline while tugging on caruncle)
What is the prog of a uterine rupture?If uterine contents infected or if it happened some time ago the prognosis is poor
Who is more likely to have an Obstructive Dystocia- dairy or beef cow?Beef
If you are concerned about obstructive dystocia, how would you choose your sire?Low birth weight sire
How large must a heifer be before you breed her to avoid obstructive dystocia?At least 60% of her adult mass
Which breed is well known for obstructive dystocias?Belgian blues
What are the CSs of an obstructive dystocia?Initially strong continuous but unproductive straining, a prolonged stage II (expulsion of fetus), which can lead to 2° inertia dystocia from myometrial exhaustion
How do you treat obstructive dystocia? (3 ways)(1) Best Tx: Lubrication & traction
(2) Next best option: Caesarean section
(3) 3rd option: Fetotomy (cut up the fetus & remove it)
What are common complications of obstructive dystocia?Damage to obturator or ischiatic nerves
Fetal death
Maternal death
Obstructive dystocia –> narrow birth canal → why are reasons for this in COWS (not heifers)Usually due to incomplete cervical dilation, Often from old trauma to cervix during previous calving/dystocia → scarring/fibrosis formation
Obstructive dystocia –> narrow birth canal → What are reasons for this in HEIFERS (not cows)Usually due to constriction of soft tissue (vag, vulva, vestibule)
Insufficient relaxation
Anatomical problems eg. Persistent hymen. May require episiotomy
What is an episiotomy?Surgical incision of the perineum & the posterior vaginal wall generally done by a midwife or obstetrician during 2nd stage of labor to quickly enlarge the opening for the baby to pass through.
Twin dystocias usually due to what? Which can result in what?Usually due to simultaneous presentation of fetii, which can cz weak or uncoordinated contraction of the stretched myometrium, weighing down of the uterus resulting in ventroflexion


Question Answer
What is Disposition?Total description of how the fetus lies in the cow = inclds fetal presentation, position & posture
What does fetal Presentation refer to? What are the possibilities?Relationship of the longitudinal axis of the fetus to that of the dam
(1) Longitudinal (Cr or Ca)
(2) Transverse (dorsal or ventral)
Which presentation is NORMAL?CRANIAL ("the diving position")
What is transverse dorsal vs transverse ventral?Dorsal: back 1st. Ventral: all 4 legs 1st
What does fetal Position refer to?Degree of rotation of the fetus about its longitudinal axis (Basically, the relationship of the fetal dorsum to the maternal pubic quadrants)
What are the different type of positions used to describe the fetus? Which is normal?Dorso-sacral (NORMAL)
Left dorso-iliac
Right dorso-iliac [1st part refers to the baby's dorsum, the 2nd part refers to what part baby's dorsum is on/against]
What do you say the position of the fetus is if they are in a transverse presentation, so their dorsum can’t be used as a point of ref?Then say according to the position of the fetal head: so either L or R cephalo-iliac (also specifying dorsal or ventral transverse, & then L or R cephalo-iliac)
What does fetal posture refer to?Relationship of the fetal extremities (head & limbs) to each other & to the rest of the fetus (e.g. neck: extended, flexed, rotated limbs: partially or completely extended or flexed)
What is a "breech" birth?Caudal presentation
Dorso-sacral position
Bilateral hip flexion
How do you correct a caudal presentation?Traction (pull it out)
How do you correct a transverse presentation?Transverse presentation converted into caudal presentation (& then caudal position can be pulled out via traction)
If you suspect the baby is in a caudal presentation, but all you can see is some of the legs, how could you tell for sure?Joints of back limbs bend in opposite directions, joints of front limbs bend in same direction (also, soles of the feet in caudally presented fetuses usually face dorsally)
Why must you be wary of dorso-iliac position? How do you fix this malposition?Rotation by 90° from the vertical czs dystocia. Do de-rotation manually by cross traction of limbs
What is the most common reason for dorso-pubic position? What must you do to fix this?Usually due to uterine torsion. Calf cannot be born in this position, so fetus has to be rotated into the correct position either by hand or through cross traction of limbs
What must you always do to correct a malposition? What other things can you do after this?Inclds retropulsion (ALWAYS do this 1st!! There is no room in the pelvis for manipulations), extension, traction & version (“twisting”)
If the calf cranially presents w/ carpal, elbow & shoulder flexion; uni- or bilateral, how do you fix this?Convert elbow & shoulder flexions to carpal flexions to resolve
How would you know when to suspect carpal, elbow or shoulder flexion?Fetal head may present outside the vulva w/ 1 (or none) foot
When fixing a carpal or shoulder flexion, what must you do to try to prevent trauma to the vagina?Cup the hoof in your hand so the vag is not lacerated
How do you fix a shoulder flexion?Get into carpal flexion position & cont from there
Malposition of head & neck → how does this usually look/present? How do you usually fix it? (In general)Fetal forelimbs may be presented outside the vulva, but no head seen.
What is 1 of the most difficult malpositions to Tx, & why?Head & neck malpositions, bc your arms are never long enough.
How would you ideally fix a neck/head malposition?Ideally, reach nose, place war bridle + use combination of retropulsion & traction on warbridle. May need to use eyehooks or a war bridle (one of the more difficult things to fix)
If you are struggling to fix a malposition of the head/neck, what should you do?If you can’t manage, do a C-section pronto, rather than wait for calf to die
What do you do to fix a tarsal flexion in a Ca presenting calf?You can feel the calcaneous on exam to know it is Ca presenting. Push the calcaneous (hock sticky outy bone) back towards uterus, & then the foot back into the birth canal
How do you fix a hip flexion in a Ca presenting cow?Retropulse fetus to create more space, then Convert to tarsal flexion → fix tarsal flexion from there. [Sometimes easier to place rope around hock, then can retropulse hips, whilst pulling hock towards you. Then move rope further down limb towards tarsus, retropulse hock + pull lower limb towards you. REMEMBER TO CUP HOOF!]

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