*Throw out any unused solution in the blue mixing bottle after 30 minutes, since the substrate decomposes. Save blue mixing bottle for future tests.*

Foals are born with little or no circulating immunoglobulins. Therefore, they are without protection against challenge from invasive microorganisms or other antigenic substances. The passive transfer of immunity occurs after birth via ingestion and absorption of colostrum. Up to 20% of newborn foals experience a partial or total failure of passive transfer, and these animals are at high risk of serious illness or death. Failure of this passive transfer can occur as a result of premature lactation, deficient suckling, malabsorption or low IgG levels in colostrum.

An IgG test can identify if a failure of passive transfer has occurred or not. This test detects the levels of IgG in the blood which are indicative of the success or failure of the passive transfer. An adequate level of IgG is 800 mg/dl of serum or greater. Levels greater than 400 mg/dl indicate a normal passive transfer, however some of these foals may still be at risk. Levels between 200 and 400 mg/dl reflect a partial failure of immune transfer while levels of less than 200 mg/dl suggest a total failure. IgG must be supplemented in these foals.

A rapid identification of low IgG levels is very important for the early initiation of treatment of immunodeficient foals. The initial testing should be done when the foals are about 12 hours old or as soon as possible thereafter. To determine the success of IgG supplementation, post-treatment is recommended.

Sample Preparation

Blood, serum or plasma samples can be used with exactly the same procedure. A blood sample can only be used if the test is run within 10 minutes after it is collected. A plasma sample collected into a purple vacutainer tube can be run immediately or later.

Samples should be labeled with the name or number of the foal and the date collected.

Test Preparation and Notes

Allow samples and kit reagents to come to room temperature before starting test (2-24 hours.) Use a timer while performing the test. Label each cup to be used with the foal's name or number and label each dilution bottle after adding the sample.

Other Important Tips:

· Store entire kit in the refrigerator when not in use. Do not freeze.
· Always reseal the Zip Loc bag after removing a test cup.
· Timing during Step 3 (the addition of the Enzyme solution - red cap to the test cup) IS VERY IMPORTANT - One (1) MINUTE.
· Never exchange reagents or test cups between different kits.
· Throw away the unused diluted sample after the test was run.

INTERPRETING THE RESULTS

Color Results Interpretation

Bright Blue A dark blue dot indicates IgG levels of 800 mg/dl or
C1 more.

Light Blue A smaller fading blue dot indicates IgG levels of 800-400 C2 mg/dl. A color similar to C2 indicates 400 mg/dl. Some supplement may be necessary for a C2 color result.

Faint Blue A color between C2 and C3 indicates 400-200 mg/dl. A faint C3 blue (C3) indicates 200 mg/dl. Supplementing IgG is necessary.

White A white cup indicates IgG levels of less than 200 mg/dl. C4 Supplementing IgG is necessary.