Hematology, blood typing, and immunology of the neonatal foal.

The research article is about the hematology, blood typing, and immunology of newborn foals. It details the changes that occur in a foal’s hematologic parameters, blood composition, and immunoglobulin levels in the early days of its life, and the implications this could have for its health.

Hematologic Changes in Neonatal Foals

• The research highlights that in the first 10 days of a foal’s life, noticeable changes in its hematologic parameters occur. These include an increase in the number of erythrocytes and a decrease in their size and hemoglobin concentration. It further explains factors such as PCV, hemoglobin, and platelet counts also decrease during this period.
• The total blood and plasma volume also reduce to a smaller extent as do erythrocyte volumes.
• The newborn foals might have immature neutrophils and a rapid rise in neutrophil numbers could be accompanied by a lymphopenia, which is low lymphocyte count in the blood.
• The level of monocytes, eosinophils, and basophils which are all types of white blood cells is low or absent initially but can change rapidly and variably during infectious processes. However, the research also points out that one should not rely solely on fibrinogen levels as early evidence of infection as the increase of these levels may lag behind the development of an infectious process.

Changes in Serum Concentrations

• After 12 hours of a foal’s life, there is generally a decrease in serum concentrations of Sodium (Na), Chloride (Cl), iron, creatinine, BUN, plasma protein, and possibly calcium. On the other hand, LDH, SAP, P, bilirubin, and glucose concentrations are higher in foals than in mature horses. This could be important to consider when diagnosing health issues in young foals.
• A foal’s creatinine might be slightly elevated during the first 12 hours after which it decreases. However, if specific abnormalities in blood composition are present, such as azotemia, hypochloremia, hyponatremia, and hyperkalemia, they might indicate a ruptured bladder with uroperitoneum.

Blood Typing and Immunology

• Blood typing in foals is considered useful for diagnosing neonatal isoerythrolysis (NI), ensuring blood compatibility between a donor and a transfusion recipient, and verifying parentage for breed registries.
• Foals have tests available for evaluating immunoglobulin levels and confirming passive antibody transfer. This helps identify foals with a condition known as Failure of Passive Transfer (FPT) where the foal doesn’t get enough antibodies from its mother to fight off infections. Such foals are given extra colostrum or plasma to boost their immunity.
• NI is uncommon but can be deadly. It’s a condition where the mother’s body produces antibodies that attack the foal’s red blood cells, triggering a hemolytic crisis. Preventive measures can be taken if the foal’s mother is found to have these harmful antibodies.