Dystocia

Question 1

what is dystocia?

Answer 1

difficult or prolonged birth, may or may not require human assistance

Question 2

briefly describe the 3 stages of parturition?

Answer 2

stage 1: relaxation and dilation of the cervix and rupture or chorioallantois
stage 2: passing of the fetus thru birth canal
stage 3: expulsion of the fetal membrane

Question 3

how does the fetus induce parturition?

Answer 3

fetal adrenal glands release cortisol

decrease in progesterone

PGF2 causes myometrial contractions

Question 4

dilation of the cervix is caused by

Answer 4

decrease in cervical tone, decrease in progesterone, pressure from fetus, release of oxytocin to induce contractions

Question 5

how does the placenta detach?

Answer 5

vasoconstriction and contractions dislodging the chorionic villi from the crypts, more than 24hrs considered pathologic

Question 6

briefly describe the circulatory system of the fetus

Answer 6

umbillical veins to the portal vein and thru the ductus venosus, to the caudal vena cava, right atrium, thru the foramen ovale to the left atrium, left ventricle, aorta, umbillical arteries. If any blood gets into the pulmonary arteru it goes thru the ductus arteriosis to the aorta

Question 7

how does the circulatory system change at birth?

Answer 7

rupture of the umbillical cord causes asphyxia which causes the fetus to gasp. this increases vascular resistance. the lungs inflate, ductus arteriosis closes, and increase in blood pressure causes the foramen ovale to close

Question 8

at birth, what acid base state are calves in? explain

Answer 8

mild mixed acidosis

met acidosis: poor perfusion of tissues=anaerobic metabolism

resp acidosis: build up of CO2 and asphyxia

Question 9

list some behavioral indicators of dystocia

Answer 9

restlesness, prolonged lying down, longer duration of tail elevation, reduced contractions, prolonged visualization of the amniotic sac to the actual birth of the calf

Question 10

list some maternal risk factors of dystocia

Answer 10

being a heifer, having a big calf, low or high body condition score, mineral deficinecies, confinement

Question 11

list some fetal risk factors for dystocia

Answer 11

being male: larger body dimensions and bigger calves
twins: malpresentation/malposture
high birth weight:

Question 12

what are some things that can be done to decrease risks of dystocia?

Answer 12

heifer selection
good dam nutrition
sire selection for birth weight and calving ease

Question 13

list 3 maternal causes and 3 fetal causes of dystocia

Answer 13

maternal: primary uterine inertia, secondary uterine inertia, abnormalities of birth canal

fetal: abnormal Ps, large offspring, fetal monsters

Question 14

what can cause primary uterine inertia?

Answer 14

failure of the uterus to contract, overstretching of the uterus from multiple fetuses, a defect in the uterus muscle, defect in hormones, atony from hypocalcemia

Question 15

what is secondary uterine inertia?

Answer 15

exhaustion of the myometrium after prolonged parturition

Question 16

sometimes dystocia can be caused by an abnormal birth canal. What sorts of conditions can lead to an abnormal birth canal?

Answer 16

small pelvis or pelvic deformities
incomplete dilation of the cervix
uterine torsions
remnants of the mullarian ducts

Question 17

uterine torsions can cause dystocia. what can cause this, and how should you proceed with treatment?

Answer 17

causes: twins, poor muscle tone, enlarged rumen, breed

tx: plank in the flank, c section, detorsion rod

Question 18

50% of dystocias are caused by

Answer 18

fetal maternal size mismatch

Question 19

fetal maternal size mismatch is caused by

Answer 19

mismanagement of heifers and bull selection

Question 20

break down the 3 Ps

Answer 20

presentation: relation of the spinal axis of the fetus to the dams axis. ex) anterior, posterior, transverse

Position: relation of dorsum of fetus to the maternal pelvis. ex) dorsosacral, dorsalpubic, dorsoilliac

Posture: relation of fetal extremities to its own bodies. ex) head ventroflexed, carpal flexion

Question 21

3 Ps?

Answer 21

this is normal. anterior, dorsosacral, and extension of head and limbs

Question 22

3 Ps?

Answer 22

posterior, dorsosacral, extension of the hind limbs

Question 23

3Ps

Answer 23

anterior, dorsosacral, left carpal flexion

Question 24

3 Ps

Answer 24

anterior, dorso-pubic, right carpal flexion

Question 25

Answer 25

ventro transverse

Question 26

Answer 26

dorsal transverse

Question 27

Answer 27

normal twins; one anterior and posterior

Question 28

Answer 28

anterior, dorsosacral, left lateral deviation of the head

Question 29

name 3 scenarios in which you should interfere with calving

Answer 29

not making progress every 30-60 minutes
abnormal Ps
prolonged gestation date only if accurate

Question 30

best way to restrain a cow for assisting with calving?

Answer 30

get her into a head gate, tie her tail, do a rectal exam, clean the perineum, and do a vaginal exam with OB sleeves and lube

Question 31

when doing a vaginal exam of a cow who appears to be in dystocia, what are you feeling for?

Answer 31

idtentify the cervix and go into the uterus, ideintify the calf with the 3Ps, and see if calf is alive by pulling the tongue, pinching the toes, or checking reflexes like palpabral or anal

Question 32

what is repulsion, rotation, version

Answer 32

repulsion: pushing the fetus back into the uterus
rotation: turning fetus longitudinally to bring it into dorsal sacral position
version: turning fetus transversly into anterior or posterior position

Question 33

what is the rule of 3?

Answer 33

a way to see if the calf will fit through the maternal pelvis: the head and legs should be able to be advanced in the birth canal, so to check this, your hand should be able to go around the calf in the birth canal

Question 34

once the head and front limbs are out and the calf chest is in the birth canal, what can you do?

Answer 34

turn it 45 degrees to prevent hip lock

Question 35

after you’ve delivered the calf, what must you do?

Answer 35

check for spares and tears, give pain mitigation, antibiotics

Question 36

after the calf has been born, what should you do to the calf?

Answer 36

check ABCs

airway: clean airway and resuscitation
breathing: rub vigorously, poke straw into nose
circulation: check HR and give drugs if neccessary