Ex 3 - Obstetrics/Dystocia

Question 1

In LA, who is at highest risk for dystocia? and what is the incidence of dystocia in cows, sows, and mares?

Answer 1

Primiparous animals are higher risk

Cows: 3-25%
Sows: 1-2%
Mares: 4-14%

Question 2

What are some causes of dystocia?

Answer 2

abnormal fetal orientation (3 P’s), developmental abnormalities, dead/sick fetus, obstructive

Question 3

Fetal-maternal mismatch (obstructive)

Answer 3

Fetus is too large/dam is too small

Cattle - esp 1st time moms
Toy dog breeds

Question 4

Maternal pathology (i.e. dec diameter of birth canal)

obstructive

Answer 4

pelvic fractures (mares)

Failure of cervical dilation
- e.g. ewes - ‘ring womb” –> perform C section

Question 5

Mechanical - abnormalities of 3 P’s (obstructive)

Answer 5

“hip lock” - fetal hips get stuck in the birth canal, due to oblong shape of pelvis
- not seen in horses (pelvic canal shape more spherical)

Question 6

Uterine inertia (obstructive)

Answer 6

Failure of effective 1st or 2nd stage of labor

1. primary –> failure to initiate labor; bitch and sow, cows (hypocalcemia)
2. secondary –> uterine fatigue following prolonged labor

Question 7

Intervention - pretty straight-forward

Answer 7

cleanliness, lubrication, expedience (progress should be made in 20-30 mins)

PE - make sure fetus okay, make sure mom okay

formulate a plan

restraint - physical and/or chemical

Question 8

Mutations (manipulations)

Answer 8

process by which a fetus is returned to a normal presentation, position, or posture

Question 9

Repulsion (manipulations)

Answer 9

pushing the fetus cranially (out of the pelvic canal and into the abdomen) –> this creates more space for manipulation

Question 10

Rotation (manipulations)

Answer 10

turning a fetus on its long axis

i.e. to move the hips of a calf fetus to avoid “hip lock”

Question 11

Version (manipulations)

Answer 11

rotating a fetus perpendicular to its long axis

• used to correct a transverse presentation
• very difficult
• C-section may be a better choice if the fetus is still alive

Question 12

Extraction

Answer 12

Withdrawal of the fetus from the dam using force/traction

Question 13

Extraction guidelines

Answer 13

• 2 people
• pull during contraction
• relax b/w contraction

Question 14

Indications for extraction

Answer 14

uterine inertia
fetus not entering the birth canal 
epidural/general anesthesia 
lg fetus 
fetotomy - after transection of retained body part

Question 15

Contraindications for extractions

Answer 15

abnormal 3 P’s
excessively large/deformed fetus
excessively small/stenotic cervix or birth canal

Question 16

Assisted vaginal delivery

Answer 16

mom awake and standing or recumbent

sedation, epidural if needed

Question 17

Controlled vaginal delivery

Answer 17

mom under GA, reduces straining and allows for repositioning of fetus

can elevate the hindquarters –. fetus naturally slides back into abdomen

no uterine contractions to help you deliver the fetus

Question 18

C section

Answer 18

Surgical procedure

fetus removed from uterus via abdominal wall incision

*procedure of choice if vaginal delivery not possible and fetus is alive

Question 19

Fetotomy

Answer 19

performed on a dead fetus to expedite removal from uterus –> cut fetus up into smaller pieces (reduces size –> easier to remove)

Question 20

Fetotomy - pros and cons

Answer 20

Pros: reduces size of fetus, avoids c section, may reduce trauma to dam, less expensive than c section

Cons: may cause uterine trauma, may take a long time, req’s several ppl, potential for injury to person performing fetotomy, live/dead status may or may not be known

Question 21

How do we determine if fetus is alive?

Answer 21

are there any fetal movements? nursing on fingers, eye reflex, pinch nose

is there a pulse? umbilical cord pulsation, heart beat

Question 22

What are some complications with interventions?

Answer 22

metritis 
peritonitis
retained placenta 
uterine, cervical, vaginal injury
reduction in future fertility

Question 23

What is the survival rate of neonates?

Answer 23

low to moderate

really depends on early recognition, duration, and type of dystocia/intervention

Question 24

What is the survival rate of dam?

Answer 24

moderate to high

Question 25

Is the dam’s future reproduction compromised?

Answer 25

pregnancy rate is good (in the absence of uterine/cervical trauma)