Stage 1 Labor

This stage usually lasts between 30 minutes to 4 hours, although Stage 1 may be shorter in multiparous mares.  It is associated with uterine contractions and relaxation of the cervix.  At this time, the mare may be exhibiting signs of colic (switching tail, looking at flanks, urinating small quantities frequently, sweating, lying down and getting up frequently).  The foal rotates from a dorsopubic position to a dorsosacral position.

            

Once it is determined that the mare is in the first stage of labor, her tail should be wrapped and the perineal area scrubbed and dried.  Late in Stage 1, the mare will be frequently lying down to roll and getting up.  This may help the fetus into birthing position. 

            

 

As the fetus and fetal membranes push up against the dilating cervix, the chorioallantois eventually ruptures and releases allantoic fluid. 

            

 

 

 

          
If the chorioallantois does not break and the velvety-red surface of the chorioallantois is presented at the vulva, it should be immediately ruptured because this indicates that the placenta is separating from the endometrium and that fetal oxygenation will be impaired.  This is referred to as “premature placental separation”. 

      

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Copyright 1999-2001
New Bolton Center Field Service Department
Students:  Keith Javic - Class of 2003, C. Nikki Conroy - Class of 2003