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.
Neonatology
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.
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 Impactions
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.
Ruptured Bladder
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
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.
