The mare and fetus are attached in utero by what is termed an epitheliochorial placenta. This means that there is no transfer of blood from the mare to the fetus during gestation. As a result of this lack of blood transfer from mare to fetus, there is no transfer of the mare's antibodies to the fetus during the length of gestation.  When the foal is born, it is totally susceptible to the pathogens in its environment. When the foal nurses within the first hour or two of life, it ingests the "antibody rich" colostrum, this is termed "passive transfer of antibodies''.  For the first 24 hours of life, the foal's intestinal tract is "open", that is to say the intestines have openings microscopic in size but large enough to allow the passage of these relatively large macromolecules, known as antibodies.  Occasionally, the mare will not produce this "first milk" or colostrum. Reasons for a lack of colostrum include Tall fescue toxicosis, premature birth, placentitis, an anorexic or "poor" mare , and maiden mares (mares giving birth for the first time) to name a few. The results of failure of passive transfer (FPT) can be devastating to the foal's survival. FPT, if allowed to go untreated can result in neonatal septicemia, "joint ill", "navel ill", pneumonia, enterocolitis, and other potentially moribund conditions.

Be sure that IGg is tested at least 12 - 15 hrs post partum and no more than 24 hours post partum.  The minimum time frame of 12 hrs allows the foal to ingest adequate levels of antibodies for the test to detect. The maximum time frame is critical due to the fact that the foal's intestines will not allow the absorption of macromolecules after about 36 hrs post partum.

Treatment of failure of passive transfer in foals can be very easy, economical and successful if it is diagnosed within 24 - 36 hours post partum. These foals can be treated with an oral IgG supplement called Serramune or stored adn collected colustrum. This product can be given within and up to 24 hours post partum. It is given per nasogastric tube at 150 cc in two doses 1 -2 hours apart.  This treatment typically will raise a foal's IgG level to a respectible level.

For foal's in which FPT is diagnosed greater than 36 to 48 hrs post partum, a different and more aggressive treatment regimen is instituted. Treatment in these foal's include intravenous administration of antibody rich plasma of equine origin. These more critical foal's are also, routinely, placed on systemic antibiotic therapy.

Failure of passive transfer in foals is a condition that can be devastating to the equine reproductive industry if allowed to go undiagnosed and untreated.  Fortunately, this condition is easy to diagnose and is easy to treat as long as it is discovered with in 24 hrs post partum.  It is imperative that horse owners that are interested in breeding be aware of the normal and abnormal conditions found in foals and mares in the post partum period.