Cesarean Section—Equine

Question 1

Explain why prompt evaluation of equine dystocia is critical for foal success, especially in regard to the length of stage II labor. What happens to the fetus if stage II labor is prolonged?

Answer 1

Mares have that diffuse organization of vasculature within the placenta, once that chorioallantoic membrane separated from the uterus, the foal no longer receives oxygenation through the placental vasculature. So, we got 20 to 30 minutes in stage II labor before that foal becomes hypoxic

Question 2

List the main causes of dystocia in the horse

Answer 2

• Fetal malposition
• Fetal congenital abnormalities
• Mare pelvic abnormalities and fetal-maternal mismatch a distant third

Question 3

Define survival rates of an equine cesarean section of mare and foal. Why is the foal survival rate so low?

Answer 3

The diffuse organization of vasculature in the equine placenta results in no oxygenation to the foal during stage II labor, rendering the foal hypoxic if stage II is prolonged past 30 minutes

Question 4

What is the most common cause of equine dystocia?

Answer 4

Fetal malposture

Question 5

(T/F) Equine dystocia is common

Answer 5

False, relatively uncommon (1-10% of foalings)

Question 6

What is the SECOND most common cause of equine dystocia?

Answer 6

Fetal congenital abnormalities

Question 7

What is this describing?
- Placental separation without rupture of the chorioallantois
- Placentitis/fescue intoxication can predispose
- Cut the chorioallantois membrane with scissors, assist delivery

Answer 7

Red Bag

Question 8

What are the main differences between assisted and controlled vaginal delivery?

Answer 8

The status of the mare

Question 9

Is this Assisted or Controlled Vaginal Delivery?
- AKA fetal manipulation with mare standing
- Sedated mare
- Perform epidural anesthesia
- Pump sterile lubrication while attempting fetal manipulation
- REFER IF C SECTION IS AN OPTION WITHOUT DELAY

Answer 9

Assisted

Question 10

Is this Assisted or Controlled Vaginal Delivery?
- AKA fetal manipulation with a mare in dorsal recumbency
- Administer tetanus toxoid and antibiotics if not previously vaccinated
- Mare is anesthetized under general anesthesia
- Elevation of hindquarters will allow for foal to fall cranially, aiding manipulation
- PERFORM WHILE THE TEAM IS CLIPPING/PREPPING FOR C-SECTION IF FOAL IS VIABLE

Answer 10

Controlled

Question 11

What surgical approach is most commonly made to perform an equine cesarean section?

Answer 11

Ventral midline under general anesthesia