Mare Eutocia, Induction of Parturition

Question 1

The mare shown in the figure was inseminated 345 days ago. Which stage of parturition is she in now?

• Stage 0
• Stage 1
• Stage 2
• Stage 3

Answer 1

Stage 2

Mare gets up and down, forceful abdominal contractions, appearance of amnion covered fetal limbs at vulva, ends with expulsion of fetus

Question 2

Stage I of the birth process in mares involves restlessness, tail swishing, mild colic, sweating, stretching, fetus re-orients itself, & cervix dilates. This stage ends with __________

Answer 2

rupture of the chorioallantois

Question 3

T/F: pH of milk in mares typically increases near foaling

Answer 3

False

pH of milk in mares typically decreases near foaling

Question 4

You are presented with a mare that aborted her fetus on the 6th month of her gestation. You examine her placenta and notice that the chorionic surface is brown, sticky, mud-like, and mucoid at the junction between the body and horn. The cervical star has no remarkable lesions. What is the most likely diagnosis?

Answer 4

Nocardioform placentitis

Nocardioform placentitis occurs away from cervical star

Question 5

In Stage II of the birth process in mares, the mare gets up and down, forceful abdominal contractions, appearance of amnion covered fetal limbs at vulva. This stage ends with __________

Answer 5

expulsion of the fetus

Question 6

What is the normal umbilical cord length in horses?

Answer 6

36-83 cm

Question 7

T/F: PGF_2a & Oxytocin are important stimulants for myometrial contraction

Answer 7

True

Question 8

What test is being performed here?

Answer 8

FoalWatch Calcium Test Kit

• Once greater than 200 ppm:
  
  • ​54% foal in 24 hours
  • 84% foal in 48 hours
  • 98% foal in 72 hours

Question 9

Which side of the placenta is being assessed here?

Answer 9

allantoic

The placenta is turned inside-out

Question 10

What is the drug of choice for induction of parturition in the mare?

Answer 10

Oxytocin

• Most common drug used – most foalings occur within 60 minutes
  
  • 10-20 IU IM once
  • As low as 2.5 IU IV has been successful

Question 11

T/F: Dexamethasone is the drug of choice for induction of parturition in the mare

Answer 11

False

• Steroids are too unpredictable – need high doses and prolonged treatment to be successful.*
• Oxytoxin is the drug of choice for induction of parturition in the mare*

Question 12

Stage III of the birth process in mares involves mild colic signs and ends with __________

Answer 12

passage of placenta

Question 13

The composition of the secretion from a mare’s udder changes over time and is indicative of impending foaling. Compared to two weeks before foaling, what happens to secretions within the udder near foaling?

Answer 13

↑ Ca²⁺, ↑ K⁺, and ↓ Na⁺

Calcium _in_creases, Potassium _in_creases, Sodium _de_creases

Question 14

Which side of the placenta is being assessed here?

Answer 14

chorionic

Question 15

What are the best predictors of readiness for birth in the mare?

Answer 15

• Udder formation, presence of colostrum
  
  • Increase in calcium content of milk
• Relaxation of cervix
• Gestational age of >330 D

Question 16

T/F: Retained fetal membranes are the most common post-partum problem in horses

Answer 16

True

Question 17

Name some complications associated with induction of parturition in the mare:

Answer 17

• Dystocia
• Premature placental separation
• Fetal hypoxia
• Dysmaturity

Question 18

Gestational age of >____ days is a good predictor of readiness for birth in the equine

Answer 18

Gestational age of >330 days

• Other good predictors of readiness for birth in the equine include:
  
  • Udder formation, presence of colostrum
    
    • Increase in calcium content of milk
  • Relaxation of cervix