Normal birth (parturition) in mares

by Robert N. Oglesby DVM

Signs of Impending Labor

During the last month of gestation, most mares go through a false labor several times before birth. These false labors look like a mild colic. They are of short duration, about 10 minutes, and the mare is easily aroused out of them. You will know that the mare means business when her water breaks. More than 60% of the births will occur at night. Frequently the night of the birth the mares appetite will be off a bit.

The teats will give a clue to when parturition will occur. Rapid filling and waxing (a white string of exudate from the nipples) indicate birth is close but some mares don't wax up while others way wax a week before birth.

A dependable way of determining the chances of birth that day is using a calcium concentration kit. Check the milk daily and when a rise in concentration occurs and peaks chances are good she will foal that night. When concentrations of calcium are over 40 mg/dl it is a good indication the foal is ready for birth. However it should not be the only indicator. False positives and false negatives occur. False positives have been associated with vaginal discharge and premature lactation. While the false negatives were mainly due to a rapid rise ocurring just hours before birth, so the rise was missed.

When 3 water hardness test kits

1. Sofchek Test Strips: Environmental Test Systems
2. Predict-A-Foal Kit: Animal Health Care Products, Vernon CA, 90054
3. Titrets Calcium Hardness Test Kit: Chemetrics

were used on prepartum mammary secretions to predict parturition, the Titrets test was most reliable and repeatable 24 hr before foaling.

Samples were diluted 1:6 in distilled water and then tested with each kit. Sofchek and Predict-A-Foal are sensitive to increasing Ca and Mg levels and may indicate slightly earlier, readiness for birth than Titrets, which is sensitive only to Ca. Even though the Titrets test is technically more difficult to perform, its results are easiest to interpret and the most consistent. W.B. Ley et al. Virginia-Maryland Reg Coll Vet Med, Virginia Tech, Blacksburg. Daytime management of the mare. 1: Pre-foaling mammary secretions testing. J Equine Vet Sci 9:88-94, 1989.

Birth

The whole process from water breaking to the foal out should take less than 20 to 30 minutes. You should keep careful track of the time during the birth. You can use this article as a form checking off each step and the exact time as it is accomplished. If the mare ever goes 5 to 10 minutes without further progress of the foal out of the birth canal you may have a problem and should seek help. Also watch the relative position of the foals parts. If they are not arranged as described, you may have a problem. During the birth, the mare will strain and groan with the contractions but she usually is fairly still. Violent motions and frequent rolling over should be viewed with the suspicion that something is not right.

Water Breaking and Amniotic Membrane

When the colicky episode is accompanied by her water breaking you know it is time. The water breaking is impressive with what appears to be several gallons of clear slightly yellow fluid rushing out the vagina. A white bubble, the amniotic membrane, will appear at the vulva within 5 minutes of the mares water breaking. This is the membrane that envelopes the foal within the placenta. At this stage the mare may get up and down several times.

Foot and Then Another Foot

A foot will appear within the bubble with the second foot following shortly at about the level of the opposite pastern. These feet should be oriented sideways or with the soles pointing down but not with the soles up. The second foot should be no further back than the pastern of the first foot. The mare usually is laying down by this time and usually will remain down for the rest of the birth if left undisturbed.

Nose and Knees

Next comes the nose between the two legs at the level between the mid-cannon area and the knees (carpus). Normally it will stick out and recede back into the canal several times with the contractions before it remains out. If you have made it this far you have gotten past the vast majority of problems that can occur during birth.

Everything Else

The rest of the neck, front legs, shoulders, torso, hips and rear legs appear a little at a time with each contraction. Frequently the hips require a few minutes to push out. If the mare is left alone following the birth, she will remain lying down for 5 or 10 minutes, recovering.

After the Birth

The foal usually begins to move around and starts breathing after the hips pass the birth canal. These movements usually free him from the membranes and break the cord. There will be some bleeding but this should slow to a drip within a minute. Do not worry if the foal breaks the cord quickly, there is not a lot of blood in the cord like we used to believe. Though there is no advantage for the foal to remain connected to the mare, I leave them alone to rest anyway. He will usually be up on his sternum within 10 minutes and standing within 30 minutes of being born. He will crash a few times before he gets the hang of it.

The foals movements arouse the mare and she will usually stand within 10 minutes of giving birth maybe a little longer. She will still have strong uterine contractions to involute the uterus and expel the placenta, so she may appear crampy and lay down several times shortly after giving birth.

The mare may also be anxious or even aggressive toward you so be careful. The best treatment for her at this time is plenty of good quality hay.

As soon as the foal is stable enough to move around he will be looking for the teats to begin nursing. His search will generally take him around the mare and he will try several different parts of her anatomy before settling on the teats. During this time, your presence in the stall will confuse him so watch from afar. This treasure hunt usually takes no more than 2 hours in a normal foal. By now the placenta has usually been released.

One of the first signs of a sick newborn is slow to rise and nurse, if your foal differs from the above times call the vet and ask for advise. If the placenta is not released by 8 hours post foaling you will need professional help.