Equine Pregnancy Dx

Question 1

methods for pregancy dx in mare

Answer 1

• behavioral assessment
• vaginal speculum examination
• transrectal palpation
• transrectal u/s
• hormonal assays

Question 2

behavioral assessment

Answer 2

• receptive to mating: estrogen influence
• non-receptive: progesterone influence
• “insensitive indiactor”

Question 3

vaginal speculum examination

Answer 3

• indicator of progesterone
  
  • cervix will be tightly closed
• insensitive indicator of pregnancy

Question 4

transrectal palpation

Answer 4

• useful at all stages of gestation
• rapid
• economical

Question 5

ultrasonographic diagnosis of pregnancy

Answer 5

• as early as 9 days post ovulation
• routinely at 14 days post ovulation

Question 6

pregnancy diagnosis day 13-18

Answer 6

• good tone in tubular tract
• distinct uterine bifurcation
• active ovaries (follicles)
• tightly closed cervix
• false positives

Question 7

diagnosis of twins

Answer 7

• ultrasonographic exam
• day 13-15 gestation
• synchronous vs asynchronous ovulation
• low survival rate

Question 8

management of equine twins in early pregnancy

Answer 8

• manual embryo crush
• best during the mobile phase (to day 16-17)
• 90% success rate
  
  • vesicle location
  • experience

Question 9

pregnancy day 20 to 25

Answer 9

• toned uterus
• narrow, elongated cervix
• rarely detectable with palpation
• guitar pick shape
• embryonic heart beat (day 24)
• day 25-allantois develops

Question 10

monitoring embryonic development during early pregnancy

Answer 10

• changing shape
• slight uterine edema
• embryo proper
• development of fetal membranes
  
  • allantois
• regression of yolk sac

Question 11

pregnancy day 30 to 35

Answer 11

• toned uterus
• narrow, elongated cervix
• hen’s egg bulge
  
  • base of uterine horn
  • day 30

Question 12

early embryonic death (EED)

Answer 12

• 1/3 to 1/4 of gestations lost in the first 30 days
• hallmark: no embryonic heartbeat

Question 13

pregnancy day 35 to 40/45

Answer 13

• good uterine tone
• narrow, elongated cervix
• tennis ball-shaped bulge
• transition from embryo to fetus
• organogenesis

Question 14

management of equine twins in late pregnancy

Answer 14

• > 40 day gestation
• occur after formation of endometrial cups (day 36)
  
  • eCG
  • persist after fetal death
• transvaginal ultrasound-guided aspiration
• cranio-cervical dislocation
• transabdominal ultrasound-guided cardiac puncture

Question 15

pregnancy day 60 to 65

Answer 15

• vesicle expands into uterine body
• child size football-shaped
• less tone in gravid horn
• non-gravid horn toned

Question 16

fetal sexing

Answer 16

• day 59-68 (65)
• genital tubercle -> external genitalia
  
  • migrates up under a tail in females
  • migrates down towards umbilicus in males

Question 17

pregnancy day 75 to 120

Answer 17

• uterus pulled ventrally
• basketball shape
• differentiate from bladder
  
  • palpate to cervix
  • ovaries at midline
• difficult to image pregnancy transrectally

Question 18

pregnancy day 100 to 120

Answer 18

• huge flaccid tract
• ovaries no longer sublumbar
• gender identification at 100 days

Question 19

pregnancy day 150 to 200

Answer 19

• uterine descent complete
• fetal ballottment consistent
• transabdominal ultrasound approach best

Question 20

ultrasound in late gestation

Answer 20

• transrectal
  
  • placental integrity at cervical star
  • fetal orbit
• combined thickness of uterus and placenta (CTUP)

Question 21

transrectal evaluation of placenta

Answer 21

• separation: ascending placentitis

Question 22

hormone assays in pregnancy

Answer 22

• progesterone
• equine chorionic gonadotropin
  
  • present whether fetus survives or not
• estrogens
  
  • active fetal placenta
  • up to 280 days of gestation-viable fetus
• minimally useful for pregnancy diagnosis

Question 23

sensitive indicators of pregnancy

Answer 23

• transrectal ultrasound best
• transrectal palpation

Question 24

insensitive indicators of pregnancy

Answer 24

• behavior
• cervical changes
• hormonal assays