Final: Pregnant Mare Flashcards
Upon which hormone does embryo transport depend?
Prostaglandin (PGE2)
When is the maximum mobility phase of an embryo?
Days 10-12
What forms soon after the the embro reaches the uterus? When does it disappear?
Embryo capsule (Polysaccharide-rich membrane between trophoectoderm and ZP)
Disappears after day 23
When does embryo migration cease? Where does it “fix”?
Day 16 (post-ovulation)
Base of one uterine horn
By convention, at what day is pregancy diagnosed via ultrasound (keeping in mind that you want to avoid missing twins)?
Day 14
At which day does the embryo start looking like a guitar pick?
Day 18
After diagnosis, when do you want to re-ultrasound the mare?
Day 24
Allantois visible ventrally
Why do you check a mare at day 60 of pregnancy?
To ensure the pregancy was not lost, after 60 days loss of embryo is unlikely
What structutres are formed by the migration of chorionic girdle cells into the maternal endometrium?
Endometrial cups
What do endometrial cups produce? When does the production peak?
Equine chorionic gonadotropin (eCG)
Day 60
Do the endometrial cups disappear faster in a mare who is on her first pregancy or on her 5th pregancy?
1st
So less eCG in maiden mares
What are the necrotic cells that roll around the allantois called?
Hippomanne
T/F: Large ovaries are normal in the early stage of pregnancy.
True
Abundant follicular development -> Secondary corpora lutea form
When are fetal gonads larger than the mare’s?
Mid-gestation
What is the relaxin source in the cow? Horse?
Cow: CL
Horse: Placenta Like the bitch
What lab test can be done to confirm pregnancy after about 90 days?
Estrone sulfate levels
Foal heat diarrhea occurs in foals born to ______ mares.
Ovariectomized
At what day are the allantois and yolk sac approximately equal in size?
30
T/F: In horses, the amnion and embryo are attached via small branching blood vessels.
False, no attachment
In which sport are mares preferred to geldings?
Polo
The genital tubercle starts in a neutral position and moves _____ in the male and _____ in the female. (Cranially or Caudally)
Cranially= male
Caudally= female
Why may an eCG level provide a false positive?
Endometrial cups could have formed and the baby lost after
i.e. Because of endometrial cups
What does an increase in the combined thickness of the uterus and placenta (CTUP) indicate?
Placentitis
What are the 3 mainstays of treatment for placentitis?
Antimicrobials (Potentiated sulfonamides)
Anti-inflammatories (Flunixin)
Progesterone (Double dose of ReguMate)
What biochemistry marker can use used to monitor the efficacy of placentitis treatment?
Serum amyloid A
What causes focal placentitis especially in the uterine body and base of the horns, resulting in a pasty brown exudate between uterus and placenta?
Hematogenously acquired Nocardioform placentitis
Causes sporadic abortion
What does prolonged deceleration of the fetal heart rate indicate?
Fetal stress
Which of these fetal samples is not commonly collected for abortion investigation?
a. Liver
b. Lung
c. Stomach fluid
d. Spinal cord
e. Adrenal gland(s)
f. Placenta
g. Kidney
d. Spinal cord
Also spleen and cardiac blood +/- maternal serum
What findings indicate EHV-1 was the cause of an abortion?
On necropsy see:
Pulmonary edema (rib impressions)
Hepatic necrosis (speckled focal disseminated)
When is a mare vaccinated for EHV-1?
Month 3, 5, and 7 of gestation
Can use live vax
What cause of abortion is associated with the Eastern Tent Caterpillar?
Mare Reproductive Loss Syndrome (MRLS)
How long is a normal umbilical cord? How many twists?
approx 55cm
4-5 twists
What is more common, unliteral or bilateral twin embryo fixation?
Unilateral
Twins?
Boo twins!
Twins bad
Twin reduction before which day of the pregnancy provides the best outcome for the other fetus?
19
What is the simplest way of inducing abortion?
Daily injections of prostaglandin PGF2a until the abortion occurs
What cause of abortion causes a thickened placenta, prolonged gestation, no udder development, and low relaxin concentrations?
Fescue toxicosis - Acremonium (fungus)
What must you rule out in a horse who is colicing in mid to late pregancy?
Uterine torsion
Correct by standing flank laparotomy
What does painful ventral edema and a caudally facing udder indicate?
Ruptured prepubic tendon/abdominal muscles
How can you minimize abdominal contractions and prevent straining?
Passing tracheal tube
Especially important if suspect/confirm abdominal muscle rupture
What is the average length of gestation?
335-342 days
Gilbert says around 340 days
Are males or females carried longer during pregnancy?
Males
Which vaccine is highly dangerous for pregant horses?
VEE
When should a tetanus vaccine be boostered in a pregnant mare?
4-6 weeks before parturition
What are the signs of impending parturition?
Vulva elongation and softening
Mammary gland: secretion, “wax” (colostrum)
Tail relaxation (ligament relaxes)
What is measured in milk to help predict when parturition will occur? What values indicate that it is imminent?
Calcium and pH
Ca: 250
pH: 6.5
Also e-lytes
What does allantoic adenomatous hyperplasia indicate?
Placental insufficiency
Foal potentially compromised
What is the simplest way to check colostrum quality?
Brix refractometer
Correlates to antibody concentration
If a mare is ready for foaling, what can you give to induce?
TINY dose of oxytocin
What is the most common fetal cause of dystocia?
Malposition: Lateral head deviation
If you see the cervical star emerge right at the start of parturition, what does it indicate?
Premature placental separation
Aka Red Bag
What does a deficiency of amniotic fluid predispose the fetus to?
Joint ankylosis
Is the breeding prognosis for a mare better after a long fetotomy or a long c-section?
C-section
What are 2 major potential consequences to retained fetal membranes?
Peritonitis
Laminitis
What can occur if you try to treat retained fetal membranes with oxytocin?
Uterine prolapse
How soon after birth does the mare ovulate?
Within 15 days
