Update on passive transfer of immunoglobulins in the foal

Abstract

SummaryFoals are born essentially agammaglobulinemic and rely on the absorption of colostral IgG for protection against infectious agents during the first few weeks of life. A mare produces colostrum during the last 2 to 3 weeks of gestation and once the foal suckles, it is rapidly depleted. Colostral quality is directly related to its specific gravity and the amount of immunoglobulin it contains can be estimated with an equine colostrometer or sugar or alcohol refractometers. Foals whose dams do not have adequate colostrum need to be supplemented with a substance rich in immunoglobulin. Equine colostrum is highly preferred as a substitute over bovine colostrum or commercial immunoglobulin products because the IgG is most readily absorbed. Failure of passive transfer can be estimated in the foal as early as 8 to 10 hours of age. There are a variety of assays that may be used in the field to rapidly estimate the immunoglobulin content in the foal. Foals with low serum IgG concentrations should receive additional IgG within the first 3 days of life. The well-being of foals with failure of passive transfer will depend greatly on the farm environment. Foals living in a clean, well ventilated barn that is not crowded are less likely to become ill than foals born into dirty, crowded conditions. Keywords:equine, foal, immunology, passive transfer, immunoglobulins

Primary diagnosis, survival and long-term outcome in young horses with problems in the neonatal period

“…Koterba and Brewer 1984, LeBlanc et al 1992, Sanchez 2005, diseases in the neonatal period are still a considerable threat for survival and well-being of foals after birth. No recent survey is available on neonatal diseases in foals and the situation in Austrian horse breeding has not been analysed so far.…”

Correlation of Serum IgG Concentration in Foals and Refractometry Index of the Dam’s Pre- and Post-Parturient Colostrums: An Assessment for Failure of Passive Transfer in Foals

“…A serum concentration of 400 to 800 mg/dl over 24 hr after birth is considered partial FPT [16,31], and a serum concentration greater than 800 mg/dl is considered adequate for protection [16,25], although many normal foals have much higher concentrations [31]. The incidence of FPT in foals ranges from 3-24%, and that of partial FPT ranges from 14-31% [2,24,27,29,31,35,37,44].Early testing for serum IgG concentration in newborn foals can identify potential cases of FPT. Several screening tests have been developed over the years for evaluating the IgG concentration in foals.…”

“…The most common risk factor for the development of FPT is considered to be poor colostrum quality of the dam (i.e., IgG concentration of<3,000 mg/dl) [28,29,31,35,46]. Therefore, a logical first step in the prevention of FPT is to determine colostrum quality in the immediate postpartum period before the foal's first nurse.…”

Proteínas séricas de potros da raça Puro Sangue Árabe recém-desmamados ou com mais de trinta dias de desmame

“…A transferência intra-uterina de imunoglobulinas maternas para o feto equino é impedida devido ao tipo de placentação que a égua apresenta, a placentação epiteliocorial difusa, que atua como barreira à passagem de grandes moléculas. Portanto, antes de ingerir o colostro, o potro apresenta concentrações insuϐicientes de imunoglobulinas (Koterba et al 1990, Jainudeen & Hafez 1995, sendo a transferência passiva via colostro fundamental na proteção contra infecções no período neonatal (LeBlanc et al 1992). O colostro ainda provém fatores de crescimento (Stelwagen et al 2009).…”