Equine Pregnancy:
1.
Gestation(length of pregnancy): around 11 months, or
approximately 340 days, with a range of 320 to 360 days.
a.
After day 40 of pregnancy, the umbilical
cord is formed.
b.
The head and body of the fetus can be
palpated (felt with the hands) at around day 85 of gestation.
2.
Pregnancy
Diagnosis:
a.
At around day 15 or 16 after ovulation,
pregnancy can be diagnosed by identification of the embryonic vesicle
during an ultrasound of the uterus.
b.
Pregnancy can also be confirmed by the
emergence of a bulge in the uterus between days 20 and 60 of gestation that
can be palpated. (It can be consistently felt after 120 days of palpation.)
c.
Day 22: embryo can be seen within the
embryonic vesicle.
d.
Day 24: heartbeat can be detected.
3.
Abortion
of the Fetus:
a.
Approximately 10 – 20% of pregnant mares
abort their fetus early in gestation.
b.
There are many different plausible
causes for abortion, including nutritional deficiencies, infections, etc.
4.
Delivery
a.
Stage
One:
i.
Mare may appear uneasy, look at her
flank, sweat, and pace around.
ii.
At this point, the mare could move
directly on to stage two or delay the delivery of her foal for a few more
hours and possibly a few days!
b.
Stage
Two:
i.
Water breaks (chorioallantois
membrane of the placenta ruptures)
ii.
Shiny-white aminion
appears, through which one and then both of the foal’s forelimbs can be
seen, followed by its muzzle and head.Once the
foal’s shoulders become visible, the rest of the foal is delivered quickly.
iii.
This stage lasts usually 20 minutes for
most mares, but may take up to 60 minutes.
c.
Stage
Three:
i.
Placenta is expelled usually within an
hour after foaling.
ii.
If it has not been expelled within 6
hours a vet should be called as horses can become very ill if it is not
removed.