With the new year upon us, it is getting very close to foaling season, my favorite time of the year. For those of you with mares which are pregnant, final preparations soon will need to be made so that the newborn foal gets the best chance at a healthy start to life. Vaccinations will be given to the mare to protect the foal, ultrasound examinations might be needed to monitor the health of the fetus, and at the least, the diet of the mare will be increased to accommodate her need for increased energy as her baby grows.
As the final days before foaling approach, the mare will be watched closely for signs of impending birth, such as enlargement of the mammary gland and relaxation of the perineum. "Waxing" also is one of the signs that indicate the mare is preparing to foal. Waxing is the secretion of a sticky, yellow substance from the mare's teats--it looks like wax, hence the name. This secretion, which is the colostrum or first milk produced by the mare, usually indicates the impending birth of a foal. Unfortunately, impending birth might mean a few hours, days, or in unusual cases, a week or more before the foal is born.
With advances in knowledge about the milk that a mare produces before foaling, veterinarians can more accurately predict foaling by looking at the electrolyte content of the milk. Determining the changes in the electrolytes, or more specifically, the amount of calcium secreted in the mare's milk prior to birth, helps veterinarians judge when the mare is about to foal. This technology greatly assists those people monitoring mares for delivery in order to be present in cases where difficult births (dystocias) might be expected or in cases where the foal is at risk of neonatal isoerythrolysis (jaundice).
This is just one of the advances achieved through the study of equine neonates and their dams. This article is going to discuss aspects of neonatal care, from the time the foal is delivered until about two weeks of age, and some of the more common problems seen in foals of this age.
In times past, many horse owners and veterinarians held to the belief that "only the strong will survive" when it came to sick foals. This meant that the weak, sick foal would never grow to become a strong athlete, so if it died, so be it. Little time or effort (and even less money) was invested in saving the sick foal.
However, as time passed, the pioneers of equine neonatology began saving these sick or weak foals from what was once considered a predictable death--and the foals were growing to become strong adults--adults which could function as well if not better than their healthier-at-birth counterparts. Today, there is an entire facet of veterinary medicine dedicated to the study of equine neonates (equine neonatology), which consists of the foaling process and the diseases and disorders of foals from birth until about two weeks of age. There also is emphasis on studying the normal and abnormal events that occur with the mare and foal in late pregnancy and just before giving birth (equine perinatology) in order to be able to recognize problems with the foals earlier, and thus prevent future problems.
Although veterinarians have studied and researched how to get mares pregnant and how to keep them pregnant since the beginning of breeding domesticated horses, we have lagged behind on how to keep the foals alive once they are born. It wasn't until about 15 years ago that the pioneers of equine neonatology began to work toward the goal of saving these sick newborns. Since that time, they have made great advances in saving foals which at one time were doomed to no life at all.
In order to do this, veterinarians are monitoring pregnant mares to enable them to recognize problems at the earliest time. Ultrasound examination of the fetus can help the veterinarian determine fetal position, estimate fetal size, evaluate the placenta, determine if there is premature separation of the placenta, and assess fetal movement and viability. Fetal heart rate also can be measured in foals as in humans to determine if the foal is distressed. By recognizing problems early, steps can be taken to avoid having to perform heroics to save the foal later. For example:
Scenario #1--Your veterinarian recognizes that your late-term pregnant mare has placentitis--an infection of the placenta--due to signs of purulent vaginal discharge and/or early milk production. Due to the risk of spreading the infection to the foal, antibiotics are administered immediately to the mare to help fight the infection. At your veterinarian's insistence, the mare is watched very closely and true to his/her warnings, your mare delivers the foal two weeks early. Because the delivery is attended, you are there to recognize the foal is a little slow to nurse the much-needed colostrum. Your veterinarian immediately gives the foal colostrum through a nasogastric tube and places the foal on antibiotics due to the mare's placenta having strong evidence of infection. The foal rebounds quickly and shows no further sign of illness.
Scenario #2--You have an older mare which has delivered many healthy foals. Therefore, you feel late-term evaluation by your veterinarian is not necessary. You never noticed the vaginal discharge or the quickly enlarging mammary gland. Your mare delivers two weeks prematurely in the middle of the night and by morning feeding time, her foal (which has never stood) is very cold and not moving. Your veterinarian gives the foal colostrum, but infection has taken hold and is so severe the foal must be treated at a veterinary hospital. The mare and foal spend two weeks in the hospital and you spend several thousand dollars on their care--but not all foals recover.
So, as you can see, careful monitoring of the mare and the foal before delivery can be a life-saver as well as a money saver. The best medicine for equine neonates is preventative medicine.
Now, let's talk about neonatal care--what to do with the newborn foal.
Caring For The Newborn
Giving a foal the best chance at survival starts with good veterinary care for the mare and good observation of the mare from the owner and/or caretaker. As a mare gets closer to her due date, a good observer will notice when the mare's mammary gland begins to fill with milk, how active the foal is inside the dam's abdomen, and how relaxed the mare's perineum is--all normal peripartum events. It goes without saying that the foaling should be attended if at all possible in order to recognize any problems during the delivery, such as dystocia (difficult birth) or premature separation of the placenta. It is terrible to wait 11 months for a foal to be born, then find the foal dead because the fetal membranes did not rupture when it was born and the foal suffocated. The simple presence of someone watching quietly during the foaling can make all the difference to the foal. (See Preparing For Foaling in The Horse of January 1997, page 25.)
Immediately after the foal is born, if at all possible, allow the mare and foal to bond properly without interruption. Of course, if the mare is aggressive toward the foal or if the foal is weak or having problems, then attending to the foal is more important.
In most cases after the birth, the mare will rest quietly as the foal acclimates to life outside of the womb. During this process, a fair amount of blood is being transferred to the foal from the dam through the umbilical cord. The foal's umbilical cord usually will break as the foal stands, so there is no need to rush in and break the cord. If the cord does not break on its own, then the cord can be manually broken by placing one hand against the foal's abdomen holding the cord and one hand just below the natural area where the cord breaks, then snapping--make sure not to pull against the foal's abdomen. If excessive bleeding occurs, then the cord should be clamped or tied with umbilical tape or even shoe laces until your veterinarian can ligate (tie) the umbilical cord surgically .
What Is So Important About The Umbilicus?
Care and monitoring of the umbilicus are very important in the newborn. The umbilicus should be cared for by applying a disinfectant solution to the umbilical stump shortly after it breaks. Recent studies have shown that the more traditional use of strong iodine solutions, 2% or 7% (Lugol's solution), are not as effective as more dilute solutions of chlorhexidine or iodine. The higher percent solutions tend to be very caustic and can lead to tissue death and abscesses. Now, it is recommended that the more dilute solutions be used since they are just as effective at killing bacteria, but do not harm the normal tissue. The umbilicus can be disinfected two or three times a day for the first few days of life with the milder solutions.
The umbilicus needs to be monitored closely since it is one of the most common pathways through which bacteria can gain entrance into the foal's body and cause infection. Infection of the umbilicus usually occurs within the first two weeks of life. Signs that indicate infection include the obvious--such as urinating through the umbilicus (which is called a patent urachus) and/or swelling of the umbilicus. The umbilicus should be examined for discharge, which first might be noticed as just moistness before pus from a serious infection is present. Pain or tenderness to the touch also is a sign of infection. If any of these signs are noticed, your veterinarian should examine the foal as soon as possible so appropriate treatment can be started.
Occasionally infection of the umbilicus is present without obvious external signs. The umbilicus is the external structure that is comprised of several structures that are necessary while the foal is in the womb. The urachus and umbilical veins and arteries make up the umbilical remnants, through which bacteria can ascend from the umbilicus and cause an abscess to form. Because these structures reside within the foal's abdomen, external signs of infection might not be obvious. Ultrasound is used routinely on sick foals to determine if part of the umbilicus is infected. If infection is present, then the umbilicus will be removed surgically to prevent further spread of infection.
Vaccinations--For A Newborn?
If you live in an area that is selenium and/or vitamin E deficient--then your mare should be supplemented during her pregnancy and during lactation because some of the selenium will be excreted in the mare's milk. Regardless of supplementation, newborn foals in our area of Central New York are routinely administered a vitamin E and/or selenium injection after birth and again on the third day of life. Animals, including foals, which have very low levels of vitamin E and/or selenium are at risk of developing white muscle disease, which is a disease characterized by muscle degeneration. The heart, as well as the skeletal muscles in the body, can be affected.
All mares routinely should be vaccinated four to six weeks prior to the anticipated delivery. This is so the antibodies to the different diseases will be passed to the foal when he/she ingests the mare's colostrum. One such disease that is easily preventable, but can be very difficult to treat, is tetanus. If a mare were not vaccinated prior to giving birth, or if the foal did not receive adequate colostrum, then tetanus antitoxin should be administered to help protect the foal.
Tetanus antitoxin is different from tetanus toxoid. The toxoid is an immunization that requires a few weeks for the horse's body to mount an immune response. The antitoxin neutralizes the toxin that the tetanus organism produces. Tetanus toxoid should be given at the same time the antitoxin is administered if the vaccination status of the mare is unknown or if the foal did not receive adequate colostrum. Regular vaccination for tetanus in the foal should begin at about three months of age.
Nursing--When To Interfere
One of the most important aspects of equine neonatology is that the foal must receive adequate colostrum--remember, foals are born without a competent immune system and they depend on their mother's colostrum, which contains antibodies (immunoglobulins), to fight off infection. A normal foal should stand and nurse by two to three hours of age. If this does not happen, then about 900 ml to 1 liter (for a 100-pound foal) of colostrum should be administered, preferably by the time the foal is six hours of age. The reason for this is that the very young foal has special cells within the gastrointestinal tract that are capable of absorbing the immunoglobulins present in the mare's colostrum. The cells die within 24 hours and the foal can no longer benefit totally from the colostrum after that time because it cannot absorb the immunoglobulins.
The weak or sick foal might take the colostrum from a bottle, but if not, your veterinarian should give the colostrum via a naso-gastric tube. If there are problems with the mare, for example, rejection of the foal, sickness of the mare, or agalactia (lack of milk production), another source of colostrum and/or milk must be found. Colostrum is banked at some large breeding farms and some veterinary hospitals. Milk replacers in powder form work well, but of course, an equine replacement in the form of a nurse mare works well, too. (See Raising And Feeding Orphan Foals in the December 1997 issue of The Horse.)
Even if your foal nurses normally, to ensure that the foal has received adequate colostrum, it is a good idea to have your veterinarian evaluate the foal within the first 18 hours of life. At that time, a test can be performed to measure the amount of immunoglobulins (antibodies) that the foal has absorbed from the colostrum. If the amount is insufficient, which is called failure of passive transfer (of antibodies), then plasma can be administered intravenously to supply adequate immunoglobulins that will be on hand to fight off infection.
Failure of passive transfer can occur for a variety of reasons, including the colostrum not being formed by the mare, the antibody content of the colostrum being low, leakage of colostrum due to premature lactation, etc. Plasma also can be administered in cases where we know foals received little to no colostrum due to death of the mare, or lack of milk production by the dam. However, there is no substitute for colostrum since it also supplies local protection for the foal's naive gastrointestinal tract.
Meconium is the first manure a foal will pass. It is comprised of the amniotic fluid that the foal swallowed during his/her development in utero. This manure, which is dark brown to black in color, can be quite firm, and most foals will have to strain to pass it. The meconium should be passed within 24-48 hours after birth. The darker meconium will be followed by much softer, lighter colored milk feces. To avoid the straining involved in passing the meconium, many people routinely give foals enemas shortly after birth. The most common enema given is probably the human product Fleet enema. A mixture of warm, soapy water administered through a flexible stallion catheter is just as effective. Repeated enemas can be irritating to the foal's rectum, so do not be overzealous. Be very gentle and always use lubrication such as K-Y jelly when inserting the enema tube.
Sometimes the meconium can become impacted within the rectum or small colon of foals--thus, the term meconium impaction. Often these impactions can be resolved with enemas, but sometimes mineral oil administered through a naso-gastric tube is required. Sometimes impactions require intravenous fluids, and in very large impactions that are refractory to treatment, they might even require surgery.
The primary sign of meconium impaction is a foal which continues to strain to defecate several hours after birth without production of meconium. Remember, foals which are straining to defecate arch their back. Foals straining to urinate sink their back.
Neonatal Maladjustment Syndrome
Neonatal maladjustment syndrome (peripartrum asphyxia) foals also are known as dummy foals, barker foals, or wanderers. This syndrome of behavioral abnormalities is caused by poor oxygen supply to the foal either during the latter part of a pregnancy (small amount of oxygen deprivation over an extended period) or during foaling. Since all cells in the foal's body need oxygen to survive, the damage caused by this process can be widespread and severe. The extent of the injury depends on the age of the foal, length of time oxygen was deprived, and how much oxygen the foal received.
Problems with lack of oxygen most obviously come from foals which have a difficult time being born (dystocias). Foals have only about 30 minutes from the onset of delivery until they need to be able to breathe oxygen. If the delivery takes longer than this limited amount of time, and if they survive, they might suffer from hypoxia (low oxygen) and could develop neonatal maladjustment syndrome. The disease also can be seen from an apparently uncomplicated delivery and from more obvious causes of decreased oxygen such as Caesarean section or premature separation of the placenta (red bag delivery).
Signs of this disease include lack of interest in nursing, inappropriate nursing behavior, depression, abnormal vocalization, seizures, and coma. Treatment of this condition revolves around supporting the foal (keeping the foal warm and hydrated), and treating any damage from the oxygen deprivation, such as kidney failure or pneumonia. The foals, depending on the severity of the disease, might need treatment ranging from intravenous fluids, antibiotics, or intravenous feeding (parental nutrition) to ventilatory support with a respirator. A fair number of foals respond quite well to treatment and go on to lead healthy, normal lives.
A ruptured bladder, which might be referred to as uroperitoneum (urine in the abdominal cavity) by your veterinarian, is more commonly seen in colts than fillies. We don't know why this happens, but we believe that it happens in most affected foals while the foal is passing through the pelvic canal or at some other time during the foaling process. Foals can, however, have defects anywhere along their urinary tract, not just the bladder, and have it result in uroperitoneum. One of these other areas is the urachus--which is the tube that connects the bladder with the amniotic sac while the foal is in the womb.
Foals with uroperitoneum usually appear normal at birth and can be seen to urinate normally. But more commonly, foals with ruptured bladders urinate only small amounts frequently. The other obvious sign of a ruptured bladder is abdominal distention. As the urine collects in the abdominal cavity, the belly of the foal gets larger and larger. Because the foals are not ridding their bodies of the urine, they can develop life-threatening electrolyte abnormalities (their potassium levels become very high, which causes heart problems). These foals need surgery to repair the defect in their bladders or wherever the leak is occurring. First, they need to be stabilized by intravenous fluids and/or draining the urine from their abdomens. Once the bladder is repaired, these foals usually do very well.
Septicemia is a term used to describe a bacterial infection that is not localized to one area, such as an abscess, but has extended to involve multiple organs and/or the blood stream. Septicemia is the leading cause of death in the neonatal foal. The infection (which usually involves gram negative bacteria) can lead to such complications as pulmonary edema (fluid in the lungs), dehydration, decreased cardiac output (which makes the foals weak and unable or unwilling to nurse), and renal failure. When the infection is severe, the foal usually needs intensive care in order to survive, and even with that, not all will make it.
Bacterial septicemia is treated with a combination of antibiotics and other drugs to fight off complications of the infection. Because foals which are sick are prone to gastric ulceration, drugs that help suppress gastric secretions also are used, such as cimetidine or famotidine. More familiar drugs such as Banamine sometimes are used to help decrease the secondary effects of the foals' bodies fighting off the infection. Intravenous fluids are given to restore hydration and help keep renal function adequate. Depending on the disease process (pneumonia, diarrhea, etc.), other therapies can be utilized.
Equine Neonatal Care Units
The intensive care of the equine neonate takes an extreme amount of work from veterinarians, technicians, and volunteers. It is time-consuming, exhausting, often frustrating, and it is not for everyone. However, there is nothing more rewarding than to see the "dummy" foal you have been watching over--which has refused to nurse for weeks--finally take her first drink of milk from her dam.
Neonatal intensive care units are quite specialized and are stocked with equipment that is designed for treating the newborn foal. Here is just a smattering of the more common supplies that are used to treat the foals in an NIC (neonatal intensive care) unit.
Veterinarians often must use ventilators to assist the foal in breathing. Other means of oxygen delivery include nasal insufflation of oxygen, where a tube runs from an oxygen source and humidified air is delivered to the foal. Specialized foal beds are used to help humans cradle the foals and keep those foals which cannot stand on their own in an upright position--which helps them breathe easier as well as provides warmth from the human bodies that gently hold them in the correct position. ECG (electrocardiograph) machines monitor the heart rate and rhythm of the neonatal heart while blood pressure tail cuffs monitor the foal's blood pressure. Heat lamps and water-filled heating pads help keep the foal's body at normal temperature, since many sick foals cannot regulate their body temperature and become hypothermic. Intravenous drips are in abundance and give the much-needed blood, plasma, dextrose (sugar), or just plain saline. Special soft feeding tubes that are placed through the nostril into the esophagus or stomach allow the foal which is too weak to nurse a supply of mother's milk. And with any young animal or human, lots and lots of diapers!
This article is an overview into the care and common problems associated with neonatal foals. I hope it has raised your awareness of what the potential problems are and how important preventative medicine is where foals and their mothers are concerned. It is always better to prevent disease than to have to resort to heroics once the disease/disorder has occurred--the old saying comes to mind: "An ounce of prevention is worth a pound of cure." Discuss with your veterinarian regular or routine examinations for your pregnant mare, and when the time comes, the foal as well. Familiarize yourself with the foaling process if you are new to the business, and be prepared for emergencies--planning is everything.
Raising and/or caring for foals is a very consuming job. The time, emotion, and work involved are staggering--especially when you are caring for a sick foal. But in my humble opinion, it is one of the greatest experiences there is.
About the Author
Christina S. Cable, DVM, Dipl. ACVS, owns Early Winter Equine in Lansing, New York. The practice focuses on primary care of mares and foals and performance horse problems.
POLL: Rabies Vaccination