Parturition Induction in the mare. Why and when? Case Report

INTRODUCTION
Some conditions require induction of parturition: colic, severe hyperlipemia, prepubian
tendon rupture, premature placental separation, hydroallantoïd, and foetal distress2,4,5.
Prolonged gestation is not a good indication1,4. Protocols using oxytocin, prostaglandins or
corticosteroids can induce parturition2,3,4,5. Most induction protocols use low doses of
oxytocin2,3,5.
OBJECTIVE
On the basis of a clinical case, this poster will discuss the indications, the methods and the
risks of parturition induction in the mare.
CLINICAL CASE
A pony mare at day 310 of pregnancy is presented for colic with poor prognosis. The foetal
parameters are good and the cervix begins to open. There is no milk in the udder. The
decision to save the foal is taken and parturition is induced by one oxytocin bolus (20 I.U./IV)
followed by an oxytocin infusion (100 I.U. in 1000ml saline). After assisted foaling, the foal
rises and sucks commercial colostrum within 30 minutes. Soon, the foal becomes depressed
and, despite treatment with commercial plasma, tube feeding and antibiotics, dies at day 2.
DISCUSSION
This case required immediate induction of foaling, which was achieved by administration
of high doses of oxytocin. Commonly, high doses of oxytocin induce dystocia because the
foal has no time to move to correct (dorso-sacral) presentation1,2,5. The risks for the foal
include absence of colostrum and foetal immaturity1,2,3,4,5. Even after day 300, the prognosis
is poor1,2,3,4. A good prognostic indicator of the foal’s maturity (lung, and other systems) is
the electrolytes concentration in the mother’s milk2,4. These protocols should be used when
foetal maturity is ascertained or as last resort1,2,3,4.
CONCLUSIONS
Foaling induction is risky for dystocia and foal outcome. It should be reserved to cases
where foal’s maturity can be assessed.