Page 88 - Speedhorse October 2018

“We try to do that in all breeds, because twins put the pregnancy and the mare at risk, but we can’t check for twins early unless the client brings the mare at the right time to be checked--and lets us check her more than once,” he explains.
If the mare does have twins and is trying
to foal too early, there’s not a lot that can be done to stop the process, but the mare can be closely monitored. “Then when she does abort or foal prematurely, there is someone there to make sure the birth can be accomplished and all goes well. With twins there may be dystocia because we are dealing with 8 legs and 2 heads that may be trying to come through a birth canal that is not designed for more than one foal,” says Sheerin.
Depending on the stage of pregnancy, a complicated birth may need to be assisted, to correct malpresentation of the twins. “In early pregnancy, when the foals are not very big when the mare is aborting, it will be easier to manipu- late them and resolve the dystocia. By contrast, if they are at 10 months it can be much more difficult because they are a lot bigger,” he says.
TREATMENT
“If there is a vaginal discharge and we do a culture, when we get the results we will start the mare on the appropriate antibiotics. Things we have to keep in mind include what the organism is and what it would be susceptible to in terms of antibiotics. We also have to make sure that the antibiotics we’re choosing are ones that we know will cross the placental barrier. Some of the drugs we use do not cross the placenta and you won’t be able to reach the source of the infection.”
These mares are also generally put on flunixin (Banamine) to decrease the inflam- mation. “We also put them on a double dose of Regumate to help decrease uterine contrac- tions. This might help prevent an abortion or premature foaling,” he explains.
If the foal has a chance to be born healthy and not too early, you want the mare to hang onto the pregnancy as long as possible. “The longer it stays in the oven, the better off the foal will be,” he says.
“In some cases if there is enough stress to the fetus, this will induce early maturation (the foal will speed up final development, to be more ready for birth). The thing we worry about, however, when a foal comes early, is the lungs being mature enough when the foal is born. In humans when it looks like the baby might be born a little too early, we can give the
Activity should be limited when a foal is born prematurely to avoid bone damage.
mother corticosteroids, which will cross the placenta and help induce maturation in the human fetus. In the horse, however, cortico- steroids don’t cross the placenta as readily, so we can’t induce that maturity. This is why we want the foal to stay in the uterus as long as possible,” says Sheerin.
“If the foal does come early and has been stressed, the lung function (if we are fortunate) has been induced and somewhat mature, but the other thing we worry about is the bones, and whether they are mature enough to bear weight,” he says.
CARE OF THE FOAL
If the foal comes early but is alive and healthy, it will need monitoring and extra care. You don’t want it walking around too much on soft, immature bones. “We’d leave the mare and foal in a stall and minimize the stresses on the bones because we worry about them being crushed. If the foal gets out and runs around this would increase the likelihood of damage to the bones in knees and hocks.” If you can limit activity and exercise, in a relatively small stall, and give them some time, they may get safely past this risk period.
“The only way to know how developed
or undeveloped the bones are would be to radiograph those joints. If you radiograph them within the first 24 hours and see that the bones do not appear to be fully developed, we’d leave
the mare and foal in the stall for more days
and then repeat the radiographs. The length
of time we leave them confined will depend on how compromised the foal’s bones are to start with, and how far they have to go to get mature enough for normal activity,” he explains.
“It may be a situation where you take radiographs again in 2 weeks, or in some cases you’d repeat the radiographs in a month. It all depends on the foal,” he says.
The other concern would be angular limb deformity. “If the limbs are valgus or varus (bowlegged or knock-kneed) this puts the weight-bearing pressure unevenly on the joints rather than straight across the whole joint. It’s greater on either the outside or
the inside of the joint. The uneven pressure increases the risk of damage to the bone.” In a normal foal there would be risk of growing up with crooked legs unless the angular limb deformity is corrected, but in the immature/ premature foal the first worry is damage to the bones. If the angular deviation is at the knees, there is time to correct those later; the first concern is to limit activity and avoid bone damage.
Other risks to the foal born from a high
risk pregnancy include the possibility of being septic, from living in an infected uterus. “This would be a concern, along with the possibility of being immature or dysmature. Some of these foals will need round-the-clock monitoring and care at a referral facility,” says Sheerin.
Chances for survival for these foals can often be improved if the problem is discovered early and the mare is given proper treatment and monitoring.
86 SPEEDHORSE, October 2018
EQUINE HEALTH