LA THERIO - Bovine Obstetrics

Question 1

What are the normal ranges for the length of each of the stages of parturition in the cow/heifer?

When will you intervene in each stage for obstetrical manipulation?

Answer 1

Stage 1 - Ends with rupture of the chorioallantois
2-6 hours (up to 8 in heifers)
Intervene: no progression to stage 2 after four hours of observation; severe discomfort, vaginal bleeding, excessive straining, rectal prolapse, rectal bleeding, downer

Stage 2 - Fetal expulsion; amniotic sac seen or has ruptured
Cows: 30 min - 2 hours
Heifers: 2-4 hours
Intervene: no progression, no efforts for two hours; too much effort for 30 minutes without progression; expulsion efforts halted for more than 20 minutes; signs of distress or fatigue, rectal or vaginal bleeding; severe vulvar swelling; calf with swollen tongue, meconium staining

Stage 3 - Expulsion of the fetal membranes (placenta)
Mechanism of placental detachment and expulsion includes: variations of BP within the placentome; collagenase and neutrophil activity; contraction of uterine horns
Should be delivered within 6 hours
> 12 hours = retained placenta

Question 2

What are the hormonal signals of parturition in ruminants?

Answer 2

Prep for parturition
Estrogen + relaxin → relax of pelvic ligaments
PGE + relaxin → cervical softening/ripening due to changes in collagen matrix
Estrogens + glucocorticoids + prolactin → vulvar and udder edema

Hormonal control of parturition:
** a mature fetal hypothalamo-pitu-adrenal axis is obligatory for initiation of parturition
stressed fetus secrets cortisol in response to ACTH → fetal cortisol decreases progesterone and increases estrogen in the dam (progesterone is converted to estrogen by 17 alpha hydrolase and 17-20 dismutase and aromatase)
the changes in steroidogenesis enhances myometrial contractions + increases mucus secretions in the cervix. They also increase synthesis of PGF2alpha by the placenta causing luteolysis.
OVERALL EFFECTS ARE: increased myometrial contractions, cervical ripening, initiation of parturition.

Question 3

What drugs would you recommend for induction of parturition in the cow to reduce the interval to calving and the risk for retained placenta?

Answer 3

CORTICOSTEROIDS, PGF2ALPHA (or its analogue cloprostenol), or combo of both
parturition should occur 24 to 72 hours after tx.

combo of DEXAMETHASONE and PGF2ALPHA gives the fastest and most reliable response!
*** induction earlier than 2 weeks before term results in poor fetal viability and increased complications such as retained placenta.

Question 4

List three maternal factors associated with an increased rate of dystocia in cattle.

Answer 4

1. Uterine torsion
2. Primary (metabolic)/secondary (exhaustion) uterine inertia
3. Birth canal abnormalities
   4.Fetal to maternal disproportion

Question 5

What two important measures can be taken to reduce the incidence of dystocia in heifers?

Answer 5

Question 6

Three common fetal abnormalities associated with dystocia

Answer 6

Question 7

What obstetrical lubricant has been found to be lethal if spilled in the abdominal cavity?

Answer 7

J-LUBE = polyethylene polymer-based lube

Question 8

Standing approach to cesarean section in the cow:

What is the preferred surgical site?

What protocol for analgesia will you use?

Uterine incision location

Most commonly used suture patterns for closure of the uterus

Post-surgical complications

Effect of fertility

Answer 8

a. Left paralumbar fossa

b. Caudal epidural w/ inverted L paralumbar block (lidocaine/xylazine)

c. Over the greater curvature, start at the tip of the horn and extend caudally

d. layer 1= continuous; layer 2 = Utrecht, Cushing, or Lembert

e. Peritonitis, Endotoxemia, post-sepsis, abdominal adhesions, retained placenta, metritis, wound infections, reduced fertility

f. None, unless complications arise

Question 9

What are the critical steps for resuscitation of calves after dystocia?

Answer 9

-Clear airway of fluid with suction and intubate if needed (do not swing calves)
-Place in sternal recumbency
-Stimulate respiration (rub calf, place finger in nose, pour cold water over the head or ear)
- check heart
- colostrum
- warm up the bb

Question 10

How is colostrum quality determined?

Answer 10

• select colostrum based on Brix %>24% (high correlation w/ IgG >100g/L )
• storage: -20C for 6 mo,-80C for 2 yrs
• thaw colostrum adequately to temp 49*C
• feed at least 3 - 4 L of high quality colostrum w/in 4 h of birth with a second feeding of 1.5 L b/n 6 and 8 h.

Question 11

What are the clinical signs of uterine torsion in the cow?

Answer 11

Question 12

What is the best method to diagnose uterine torsion and its direction?

Answer 12

Question 13

On which side would you lay down a cow to resolve a uterine torsion using the rolling technique with a plank on the flank?

Answer 13

Rolling when the cervix is closed or very tight: the cow is placed on lat recumbency on the side of the torsion (ex: CCW → place on the L side). The fetus and uterus are maintained stable using a plank (12 - 15 feet long and a foot wide) on the flank. Cow is rolled. Resolution of torsion is verified by transrectal and vag exam..

Question 14

What are the predisposing causes of uterine prolapse in the cow?

Answer 14

Question 15

What approach would you use to treat a cow with septic metritis?

Answer 15

• 2 -14 days postpartum
• broad spectrum Abx: ceftiofur, penicillin, ampicillin, oxytet
• NSAIDS
• fluids
• Supportive Tx
• if a calf is in posterior position - look for a TWIN!!!!