Detection of hypogammaglobulinaemia in neonatal foals using the glutaraldehyde coagulation test.

The glutaraldehyde coagulation test was adapted to foal serum to determine adequacy of the colostral-intestinal transfusion of IgG. The test is performed simply by mixing one volume of reagent with 10 volumes of serum and observing the coagulation time. The required glutaraldehyde concentration was established for various threshold levels of IgG as determined by radial immunodiffusion. The analysis consisted of 140 serum samples from foals. Sera with low IgG levels require high glutaraldehyde concentrations and vice versa. The 4 g/l threshold generally accepted for IgG adequacy, was achieved at the optimum diagnostic sensitivity and specificity level by using 10% solution of glutaraldehyde and observing the coagulation at 20 minutes. The use of a 5% glutaraldehyde solution resulted in a cut off level at 5.5 g/l, respectively. The glutaraldehyde test is the cheapest field test for IgG-adequacy.