Page 483 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

458 CHAPTER 2

VetBooks.ir 2.69

Fig. 2.69 This is a normal
expulsed placenta showing the
allantochorion to the right and the
amnion remnants to the left.

of amnion can be as little as 10 minutes, with within 1–4 hours of the foal being born. It is
the foal delivered within 20–30 minutes (range important to differentiate the abdominal pain
10–60 minutes). The foal takes an active part in of this stage from that which can occur in some
its delivery and if it has any abnormality, this can post-partum complications. The placenta often
substantially affect the process. Signs of second- hangs from the vulval lips, but it should be tied
stage parturition include: rigorous uterine and up if it drags on the ground. Once it is expelled
abdominal contractions of up to 1 minute in it should be examined for completeness and
length, often with the mare recumbent; rest abnormalities (Fig. 2.69).
periods of several minutes during which she
may reposition herself; presentation of the INDUCTION OF PARTURITION
whitish amnion at the vulval lips; rupture of the
amnion and release of the yellowish amniotic Induction of parturition should never be undertaken
fluid; presentation of the foal’s forelimbs (one without first assessing the viability and maturity
slightly behind the other with the head resting of the fetus and the stage of gestation of the mare.
on the carpi); further contractions until the foal Failure to ensure that the mare and fetus are ready
is expelled to hip level, when the mare often for birth can result in serious problems for both,
takes a rest; and final expulsion of the foal, including premature placental separation, dystocia,
sometimes associated with the mare standing retained placenta, foal prematurity or dysmaturity,
(more common in maiden mares). The umbilical failure of passive transfer (FPT) and neonatal malad-
cord usually separates when the foal moves justment syndrome. Indications for induced deliver-
or the mare stands and it is still regarded as ies include high-risk pregnancies, history of difficult
preferable to allow this to happen naturally as it foalings or abnormal foals and injuries to the mare
aids haemostasis. The mare and foal should be such as prepubic tendon rupture or pelvic injuries.
left quietly at this stage to recover from their Mares should not be induced purely for the conve-
exertions and to start the bonding process. nience of the owner or attending personnel, and it is
• Third stage. This is associated with the important to appreciate future breeding options for
passage of the placental membranes and the the mare and the likelihood of foal survival if induc-
onset of uterine involution, and usually occurs tion is performed.