Therio- Bovine- Obstetrics and dystocia 1

wilsbach's version from 2015-11-04 18:34


Question Answer
abnormal birth is calleddystocia
normal birth is calledeutocia
what are the three kinds of dystocia?(1) Primary Inertia (2) Obstructive Dystocia (3) Secondary Inertia
explain dystocia due to primary inertiaForces that propel the foetus are absent
explain obstructive dystociaForces that propel foetus are normal, but no progress of fetus through birth canal
explain dystocia due to secondary inertiaconsidered a complication of obstructive dystocia due to exhaustion of myometrium
what are some reasons there might be a dystocia due to primary inertia?(Forces that propel the foetus are absent) #1 cause 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 causes 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 secondary inertia]]
MOST COMMON causes of dystocia she says areFeto-maternal disproportion and 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 cause a primary inertia uterine dystociaHypocalcaemia, hypomagnesaemia, Hypoglycaemia, ketosis
how is it that Foetal malformation (monsters) can cause dystocia?either does not initiate partus (primary inertia)or malformation results in dystocia (obstructive dystocia)
hypocalcemia would cause what kind of dystocia?primary inertia
Clinical signs of hypocalcaemia?Recumbent, Torticollis (head flexed so it looks like shes 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, hypoca can cause BLOAT
If you see a recumbent cow at term looking a bit bloated without myometrial contractions, you think..subclinical hypocalcemia
what might be some causes for fetal malformations which would cause dystocia?Viral infection, Plant teratogens, Congenital, pesticides, chemicals, Pharmaceuticals
what are some Viral infections in utero which can cause fetal malformations?BVD, Rift Valley Fever
what are some Plant teratogens which can cause fetal malformations?Lupines, poison Hemlock, Locoweeds, Tree tobacco
what are some congenital fetal malformations?Bulldog calves in Dexters & Herefords
(FYU) examples of Different malformations of the fetusHydrocephalus, Schistosomus reflexus, contorted joints (arthrogryposis, torticollis, kyphosis, scoliosis, lordosis = “Crooked calf syndrome”), foetal ascites, foetal anasarca, chondrodystrophia foetalis, muscular hypertrophy, perosomas elumbis, cyclops, amorphus globosus
what is Perosomus elumbis?partial or complete agenesis of the lumbar, sacral, and coccygeal area and accompanied by posterior bimelic arthrogryposis characterized by ankylosis of joints with 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 with severe developmental anomalies of the spinal column and consequent failure of the abdominal wall to close. The spine is bent dorsally so that the head and tail curve towards each other and the fetal viscera are free floating in the amnion.
what is Amorphus globosus? Instead of a typically developing fetus occurs thereby to form one of hairy skin covered, more or less spherical structure, the shares of all three germ layers contains; the differentiation of its contents can vary greatly. A amorphus globosus is lack of functional organs not viable
where does uterine rupture usually occur?along the major curvature just cranial to cervix
what are some of the main causes of uterine rupture?Pre-existing weakness of the uterine wall, Following ischaemia 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 treatment vary?)(1) if less than the width of a hand, then Repair may not be necessary if small and dorsal due to rapid uterine involution, so just do Repeated oxytocin injections + 7-10 days of antibiotics. (2) if bigger than the width of a hand, then Often dystocia required C-section to repair uterus. Need to do One 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 a 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 clinical signs of an obstructuve dystocia?initially strong continuous but unproductive straining, a prolonged stage II (expulsion of fetus), which can lead to secondary inertia dystocia from myometrial exhausion
how do you treat obstructive dystocia? (3 ways)(1) best tx: Lubrication and traction. (2) next best option: Caesarean section. (3) third option: fetotomy (cut up the fetus and remove it)
what are common complications of obstructive dystocia?damage to obturator or ischiatic nerves, fetal death, and 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--> why are reasons for this in HEIFERS (not cows)Usually due to constriction of soft tissue (vag, vulva,vestibulum), Insufficient relaxation, or even Anatomical problems eg. Persistent hymen. May require episiotomy
what is an episiotomy?surgical incision of the perineum and the posterior vaginal wall generally done by a midwife or obstetrician during second 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 foetuses, which can can cause 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 = includes foetal presentation, position and 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 first. ventral: all 4 legs first
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), dorso-pubic, left dorso-iliac, right dorso-iliac [first part refers to the baby's dorsum, the second part refers to what part baby's dorsem is on/against]
what do you say the position of the fetus is if they are in a transverse presentation, so their dorsem cant 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, and then L or R cephalo-iliac)
what does fetal posture refer to?relationship of the foetal extremities (head and limbs) to each other and to the rest of the foetus (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 (And 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 causes 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?includes retropulsion (ALWAYS do this first!! There is no room in the pelvis for manipulations), extension, traction and version (“twisting”)
If the calf cranially presents with carpal, elbow and 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?foetal head may present outside the vulva with one (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 and cont from there
Malposition of head & neck--> how does this usually look/present? how do you usually fix it? (in general)foetal forelimbs may be presented outside the vulva, but no head seen.
what is one of the most difficult malpositions to tx, and why?head and neck malpositions, because 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 and traction on warbridle. May need to use eye hooks 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, and then the foot back into the birth canal
how do you fix a hip flexion in a Ca presenting cow?Retropulse foetus 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!]