Lab Section: Clinical Pathology
Description: Turbidometric Immunoassay test for IgG in serum
Min Sample Volume: 1 mL
Collection Container: plain glass or plastic tube
Coolant: Refrigerate
Test Target: Antibody
Test Days: M-Sa
Test Turnaround (business days): 1-2 days
This test has supplanted radial immunodiffusion measurement for equine IgG quantification. It measures total IgG (not specific isotypes) and is usually performed as the definitive test for passive transfer of immunity in foals. It can also be used to measure total IgG concentrations in older horses (e.g. for immune deficiencies). Passive immunity from the ingestion of colostrum within the first few hours after birth is critical to the health of the newborn foal. Failure to suckle within the first three hours after birth may result in low or absent immunoglobulin levels. This may be associated with an increased incidence of infections, such as sepsis, “joint ill”, or uveitis. Additionally, poor colostrum quality or premature lactation in mare could cause low IgG in foals even when suckling occurs within 3 hours of birth. All newborn foals should be tested for IgG status within 12-48 hours of birth, to allow for timely plasma transfer to assist in the foal’s response to pathogens. When this test is used results are expressed quantitatively, rather than simply above or below particular cut-offs. Results achieved with in-house rapid testing platforms may be complimented with this test for quantitative results to assist in decisions to transfuse plasma and response to plasma treatment. Critically ill and/or sick foals should also be tested to determine IgG level to assist in treatment and prognosis.
