Failure of Passive Transfer

The foal with failure of passive transfer should have his immunoglobulins re-checked after receiving a plasma transfusion to ensure that it has reached 800 mg/dl. Foals with septicemia as a result of their failure of passive transfer may require more plasma than non-infected foals. It appears that the immunoglobulins in these foals are used up more quickly in fighting the infections. Rechecking the immunoglobulins in these foals 4 to 5 days later may be important. Additional plasma may need to be administered.

Colostral immunoglobulins begin to disintegrate as soon as they are absorbed. In normal foals they disappear from the blood stream around 2 to 3 months of age. As they disappear, the foal begins to make his own immunoglobulins. The foal reaches adult levels of immunoglobulins around 4 to 5 months of age.