Failure of passive transfer in foals

Abstract

Foals are born with a naive immune system, and rely upon the ingestion and absorption of immunoglobulins from the dam's colostrum to obtain passive immunity. Failure of passive transfer (FPT) is the most common immunodeficiency disorder in the horse and is associated with an increased risk of infectious disease and mortality. Routine screening is recommended, to allow early detection and treatment. Management of failure of passive transfer is dependent on the age of the foal at the time of diagnosis, but primarily involves intravenous plasma administration or the administration of colostrum (orally or via nasogastric intubation). Given the association between IgG concentration and clinical outcome, early detection and management of FPT are important in reducing morbidity and mortality in neonatal foals.

Immunity transfer in mule foals fed with good IgG quality colostrum

“…Compared to donkeys [ 19 ] and horses [ 31 , 32 ], where serum IgG concentrations are generally performed around 12 and 12/18 h of life, respectively, it seems that passive transfer of immunity assessment can be done earlier in mules. This might enhance faster decision and intervention in case of need, improving the mule foals' chances of survival [ 17 ]. In the case of doubt, a second evaluation should be performed at 24 h as reported for other species.…”

“…The gold standard for the determination of IgG concentrations in body fluids is the Serum Radial Immunodiffusion (SRID) assay which has the disadvantage of being expensive, time-consuming and results are susceptible to human errors or commercial kits used [ 15 , 16 ]. More feasible tools for estimation of serum IgG concentrations in foals are quick tests, such as the SNAP test (IDEXX SNAP® Foal IgG Test - SNAP® Foal IgG) [ 17 ]. These tests are easy to perform, practical in the field and relatively cheap, however, they are semi-quantitative tests giving ranges of IgG concentrations (≥800 mg/dl, 400–800 mg/dl, or < 400 mg/dl) instead of the exact amount of immunoglobulins absorbed.…”

Fetal rhabdomyoma in a Thoroughbred filly

“…Serum haematology revealed no abnormalities, and IgG testing performed at 24 h from birth revealed an adequate transfer of passive immunity (>800 mg/dL) (Mackenzie, 2020 ). Ultrasonographic examination of the mass was performed under standing sedation (diazepam 0.02 mg/kg IV – Diazepam injection, 10 mg/2 mL, Hameln) using a linear probe (7.5‐12‐MHz; GE Healthcare – LOGIQe, Munich, Germany).…”