Oklahoma Cooperative Extension Service • Division of Agricultural Sciences and Natural Resources
David W. Freeman, Extension Equine Specialist
Steven H. Slusher, Professor, Veterinary Medicine and Surgery

The birth of a foal is a highly anticipated event for many horse owners. Early life management decisions determine the future health and the relative success of the entire life of a foal. It is important to make choices based on research information that promotes the health and vitality of foals.

Pre-Parturient Foal Protection

Protection of the newborn foal should begin well before the anticipated birth. Approximately fourto six weeks prior to parturition, the dam should receive booster vaccinations to provide high levels of immunoglobulin (antibody) in her colostrum (first milk). As a minimum, a tetanus toxoid booster should be administered. In addition, sleeping sickness, influenza, and strangles boosters may be given. Use of these and other vaccine boosters will depend on knowledge of anticipated farm-specific diseases or the recommendation of local veterinary professionals.

If a mare is known or suspected to have produced a foal with neonatal isoerythrolysis (see explanation below), she should have a blood test taken to examine for the presence of anti-red blood cell factors. This test can be done approximately three weeks prior to the anticipated delivery date. If positive results are found, preventive measures as described later in this fact sheet can be undertaken.

Newborn Stress Management

Several management practices should be conducted soon after birth. Management procedures and schedules vary from farm to farm, but two areas of concern on all farms should be the detection of immunoglobulin transfer and physical exams.

Antibody Transfer

The foal relies on absorption of antibodies from the mare’s colostrum for early life protection against many bacterial and viral pathogens that cause infections. This transfer is especially critical for resistance to disease in the first two to four months of life.

There are several potential causes for failure of passive transfer of antibodies, including:

1. Low antibodies levels in the mare’s colostrum.
2. Colostrum leakage from the udder prior to the foal birth.
3. Failure of the foal to absorb colostrum (usually induced by the stress caused by ingesting protein substances before nursing colostrum).
4. Failure of the foal to nurse prior to eight hours of age.
5. Premature birth of the foal.

Solutions to Antibody Transfer Failure

One of the oldest solutions to the problem of transfer failure is to administer colostrum to foals that have not nursed or obtained enough protection because of deficiencies in the mare’s colostrum. Colostrum can be collected from mares with a history of high levels of immunoglobulin production and stored by freezing for up to 18 months. However, you must be aware that a hemolytic disease of newborn foals, neonatal isoerythrolysis, is a possibility, either from ingested colostrum from the dam or from administered colostrum from other mares.

This hemolytic disease of newborn foals follows the ingestion of colostrum containing antierythrocyte antibodies which destroy the foal’s red blood cells. In natural cases, the foal inherits this detrimental antibody from the sire, and sensitization of the mare is a result of transplacental hemorrhage late in gestation or during parturition. It is rare in foals born to first-foaling mares. The mare’s sensitization to the foal’s red blood cells most often involves the A and 0 blood group determinants. Within 24 hours of colostrum intake, the foal shows weakness and lack of attention. By 48 hours after ingestion, clinical signs of anemia, jaundice, and labored breathing are evident. Treatment and prevention involve:

1. A pre-parturient blood test of the dam for anti-rbc factors.
2. Blood tests of the sire and dam, or colostrum, plasma, blood donor screening for the A and 0 blood groups.
3. Muzzling the foal until colostrum has been removed from the dam’s udder, and then supplying a safe colostrum source.
4. Veterinary therapy and blood transfusions for the affected foals.

Contact a veterinarian for donor screening or foal treatment if there is any evidence that this disease may be a problem.

Frozen colostrum should be thawed in warm water when ready to administer. DO NOT THAW COLOSTRUM IN A MICROWAVE OVEN. Microwave ovens will render antibodies unusable by the foal. Several pints (5 to 6) will need to be administered in four or more doses over the 12-hour period following birth via suckling or stomach tube. Optimally, colostrum administration should be completed during the first eight to 12 hours after birth.

Another method that can be utilized is intravenous plasma transfusion to the foal with plasma that has been taken from a suitable plasma donor. Plasma may be obtained by collecting blood, usually with veterinary assistance, from donors ideally screened against the A and 0 blood groups.

Alternative sources of plasma, in an emergency, include the dam, yearlings of either sex, older geldings, or commercially produced plasma. When preparing plasma from on-farm sources, blood is collected into sterile containers. The red blood cells are totally removed, leaving the plasma containing the antibodies available for transfusion into the deficient foal. The amount of plasma needed depends on the type and number of environmental pathogens, the foal’s immunoglobulin level, and the immunoglobulin content of the plasma. Besides expense, the major problem with purchased plasma is that it may not include immunoglobulins effective against the pathogens that are present in the individual foal’s surroundings.

Testing Procedures for Immune Transfer

Several testing procedures are available that estimate the antibody levels in the mare’s colostrum or the level of antibody in the foal’s blood.

A quantitative measurement of antibody production in colostrum can be obtained by the use of a colostrometer (Lane Manufacturing). The colostrometer measures the specific gravity of a milk sample—the higher the specific gravity, the larger concentration of immunoglobulins. Golostrum-specific gravity values recommended by the colostrometer manufacturers are that sample values greater than six units are acceptable for use or can provide adequate immunoglobulin for a foal; colostrum specific gravity values greater than nine units are required if the colostrum is to be frozen for future use.

Colostrometers are not used frequently because they are of little value in determining the amount of actual transfer and levels in the foal. The most accurate developments in testing have centered on measuring the immunoglobulin content in the foal’s blood. These tests are conducted usually between 14 and 36 hours following birth. The tests vary in cost, accuracy, and the need for trained personnel. Some of the more commonly used tests are a zinc sulfate turbidity test and enzyme immunoassay (GITER - AgriTech Systems). These tests can be obtained through your veterinarian. Current guidelines, obtained from extensive field research, would indicate that:

1. Failure of passive transfer exists when IgG levels are less than 400 mgldl of lgG (requires antibody transfusion to foal).
2. Partial failure of passive transfer exists at 400 to 800 mgl dl of IgG (careful observation of the foal because many is recommended become ill if exposed to overwhelming levels of disease).
3. Adequate or protective levels of IgG are present when the tests indicate greater than 800 mg/dI of IgG is present.

No specific clinical signs of failure of passive transfer are evident without testing, except for infection sthatmay develop in the foal as early as in the first three weeks of life.

Physical Examination

A general physical examination of the newborn should be conducted within several hours afterbirth. This examination will allow forthe early detection and treatment of clinically detectable abnormalities. General exams include examination and observation of the eye for pupil response, as well as eyelid and corneal abnormalities. The heart sound and rate, lung sound, mouth and leg conformation, and umbilical stump should also be checked. The foal’s behavior should be monitored to determine responses in attitude, vitality, and general posture. It is important that the person conducting the exam is a qualified veterinarian or someone experienced in foal behavior and typical foal responses.

Routine procedures include treatment of the umbilical stump with a 2% iodine solution (or equal parts of 7% tincture of iodine and glycerin), a warm water or commercially prepared enema, physical exams, and possibly the administration of antibiotics. If a pre-parturient tetanus toxoid vaccination was properly administered to the damand if the foal’s IgG levels are tested and found adequate, administration of tetanus antitoxin to the newborn would be unnecessary. Likewise; the dam would not need tetanus antitoxin administration at parturition. Exact procedures will depend on the history of the mare, and recommendations will vary slightly from farm to farm. Consult with your veterinarian so that he or she can make recommendations and is aware of your general practices should a problem arise.

Nursing Foal Stress Management

Several procedures will need to begin during the period while the foal is nursing. These decisions include the need for handling, vaccinations, deworming, and creep feeding.

Early Life Handling

Gentling techniques for young foals will vary from farm to farm. Imprint training is started on some farms immediately after parturition and as soon as the newborn foal has nursed. It is recommended that reinforcements of the imprint training be provided at later intervals. Many farms start procedures to familiarize the foal with human contact after a few days of birth. Gentling helps reduce weaning stress. It is important that gentling techniques imprint the basic behavior of the foal toward respect of humans rather than fright or fear. Also, early learning experiences will greatly assist in teaching the types of behavior that will be allowed around humans. Rubbing, holding, and scratching movements are used to begin the halter breaking techniques, and many farms halter break foals within several months of age as farm management practices will allow.

Vaccinations and Deworming

Vaccination needs will vary with location, and will partially depend on the vaccination history of the mare. Commonly recommended vaccinations include those against rhinopneumonitis, influenza, strangles, tetanus, and sleeping sickness. Vaccinations are started at two to three months of age. If not already started, deworming programs also should begin at this time. It is especially critical to deworm against bloodworms and roundworms in young foals.

Creep Feeding

The foal’s nutrient requirement will exceed the availability of nutrients from milk within three to four months following birth. Also, research shows that foals on creep feed will have less weaning stress than those denied creep while still on the mare. Creep rations should contain between 16% and 18% crude protein, and about 0.8% calcium and 0.6% phosphorus. Foals should be allowed access to creep within several days following birth, but most will not consume large quantities of creep until reaching three to four months of age. Intake of creep will vary from 0% to as much a 3% of foal body weight per day. Foals can be given full access to creep as long as a clean, fresh feed supply is maintained.

Weaning Management Age

Foal’s are usually weaned at four to six months of age, but they can be weaned earlier. Early age weaning, such as after several days or weeks following birth, may be required in the case of mare death or mare’s refusal of the foal. Also, some farms practice early weaning so that foals do not have to be transported with mares to breeding farms. Early weaning requires more intense foal care and management.

Early weaned foals will need to be taught to consume a milk protein-based milk replacer. A bucket can be used, and it is important that the foal have continuous access to fresh supplies. The bucket can be placed in the corner of a stall at wither height to the foal. Initially, the foal will have to be taught to drink from the bucket. The handler can hold the bucket below head level of the foal while allowing the foal to lick and suckle milk replacer on the handler’s hand while placed above the liquid in the bucket. Encouraging the foal’s nose to touch the milk replacer by lowering the hand in the milk as the foal is licking or suckling will help the foal "discover" the milk in the bucket. Most foals quickly learn to drink directly from the bucket. A nipple bucket may be needed for a foal that is unable to drink from a bucket. Milk replacer supplies will need to be checked several times a day. Initially, expected consumption rates are about one-half to one gallon per day. Consumption should increase so that foals are consuming three to four gallons per day at three to four weeks of age.

Weaning Methods

The weaning method used will depend partially on facility and labor constraints. Research has indicated that foals weaned in pairs have less weaning stress than those weaned alone. Also, gradual removal from sight and smell of the mare will assist in minimizing weaning stress. A common practice is to wean two foals at a time and place them in a weaning stall. Mares are placed in adjoining stalls that allow for smell and sight, but deny physical access. Mares are removed from the stalls after a week. Foals are moved to a weanling paddock following several days after the mare removal.

Oklahoma Cooperative Extension Service • Division of Agricultural Sciences and Natural Resources
David W. Freeman, Extension Equine Specialist
Steven H. Slusher, Professor, Veterinary Medicine and Surgery

Visit: Oklahoma State University for more information on the health of your horse.