The foaling season is getting into full swing now. The birth of a foal or even several foals is always a matter that breeders are looking forward to with great anticipation. But what is a birth really like, what are the things to look out for and what to do when things are not going as smoothly as everyone hopes?
When a mare is close to foaling we can roughly distinguish between three phases of contractions: phase I will start with a mild tightening of the uterus. Phase II is the pushing phase with contractions of uterus and abdominal muscles that will bring the foal’s front legs and head forward into the pelvic cavity. The outer amniotic sac will burst producing a wave of amniotic fluid. From that moment onwards the birth must take place within 45 minutes otherwise the foal may be deprived of oxygen. This is because the contractions cause the breaking of the waters which means that less and less oxygenated blood will be transported to the foal via the umbilical cord.
Be there!
It is always wise to make sure that you are present during foaling! In most cases everything will take care of itself, but when things do tend to go wrong there will be little time for interventions. As soon as the mare gets into the pushing phase the front feet should be visible within ten minutes. This is the moment to check if the foal is in the correct foaling position. If you cannot locate either one or both legs or the head you should immediately call the veterinarian. While you are waiting for the vet’s arrival it is a good idea to keep the mare on all fours and try to walk her around. This way you may be able to delay the pushing stage.
Two horns
The equine uterine corpus contains two horns. Normal procedure is for the foal to grow in the uterine corpus with its head, neck, forelegs and upper part of the body, while its hindquarters grow in one of the horns. This can be worked out by looking at the afterbirth: there will be one large pocket that enveloped the hind legs and one tiny empty one. In this situation the foal will be born in a forward presentation, i.e. face forward with the head and forelegs being the first to pass through the birth canal.
If it is the forehand that develops in one of the horns instead of the hindquarters, the foal will be born in a backward presentation. In this situation pressure is put on the umbilical cord while the foal’s head is still in the mare. If at this stage the actual birthing takes too long the foal is likely to get a shortage of oxygen and distress might cause it to breathe in amniotic fluid.
Transverse presentation
Another possibility is the transverse presentation. If this is the case both forehand and hindquarters have each developed in one of the horns with probably just one or two legs having grown in the corpus. Then there will be little enlargement of the corpus so it will stretch to a long and narrow form caused by the growing foetus inside the horns. A foal in this position cannot be delivered because either its belly or back is facing the birth canal.
A foal in a transverse presentation cannot be repositioned and cutting it into pieces is usually no option either even when the foal has already died. As explained above, the reason for this is the long and narrow shape of the uterus corpus because the foal has developed in the horns. A veterinarian would need exceptionally long arms and even then you would at the very best be able to reach the belly or breast. It is possible to deliver the foal by a fetotomy (cutting up) if you can do this with one or two, at most three quick cutting actions. If more cutting actions are needed or the whole process will take longer than 45 minutes the mare will become exhausted and you might cause serious damage to the birth canal, which will obviously have an effect on post-delivery recovery.
Good prognosis
Fortunately, the prognosis for a caesarean section in a mare is good (90%), even for the mare’s future fertility percentage. Usually, a quick and well-executed caesarean section takes less of a toll on the uterus than a lengthy repositioning process or fetotomy.
The foal’s chances are less favourable. According to literature, chances of a live foal average around 70 minutes from the onset of the pushing stage to the caesarean. This study has been based on the English Thoroughbred. Studies of the Dierenkliniek Wolvega have revealed that in the case of Friesian horses this process may last up to twice this time and still result in the birth of a live foal.
As posted in the April KFPS Newsletter
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