blueprintminis
Well-Known Member
Have you ever had a mare deliver her foal, stand up and start to turn around to lick it and have the placenta plop out onto the bedding while it is still attached to the foal by the umbilicus? If so, then the mare had premature placental separation. This is not the norm in full sized horses. It usually takes 30-60 minutes or longer for full sized mares to pass the placenta. When the placenta comes out right away or within minutes of the delivery of the foal then the placenta was already separating from the wall of the uterus while the foal was being delivered. As the placenta separates, the oxygen supply is reduced. The more separation, the less oxygen getting to the foal. As the oxygen level in the foal declines the foal become "sedated". It is actually starting to die from lack of oxygen to its brain while it is being delivered. These are the foals that do not move when they hit the straw. That is why the birth sac does not break. For some reason, mini mares placentas tend to separate earlier than their larger counterparts. Interestingly, draft horse mares are the most likely to have retained placentas (their placentas don't want to separate from the uterine wall even after the foal is expelled). This tendency for early placental separation is the number one reason it is so important for someone to be present at delivery time to ensure the birth sac is pulled away from the foal's face as soon as the head is out of the mare. Yes, other factors can lead to an extra thick/tough birth sac, but a foal that has been deprived of oxygen for too long during the birth process won't be moving at all so it doesn't matter how thick or thin the birth sac is.