Blood gas analysis, hematology, biochemistry and Apgar score during the first 24 hours of life of Mangalarga Marchador foals.

Research Overview

• This study investigated changes in blood oxygenation, biochemical, hematological parameters, and Apgar scores during the first 24 hours after birth in healthy Mangalarga Marchador foals.
• The goal was to establish reference values that can help assess neonatal foal health and detect potential complications early.

Background and Aim

• Equine neonatology has advanced, allowing continuous monitoring of pregnant mares.
• Despite this progress, there is limited data on normal oxygenation and biochemical levels in newborn foals during their critical first day.
• The study aimed to fill that gap specifically for the Mangalarga Marchador breed by tracking blood gas, hematology, biochemistry, and Apgar scores from birth to 24 hours postpartum.

Methods

• 30 healthy Mangalarga Marchador foals were selected for the study.
• Blood samples were collected at five time points:
  • At birth (T0) from the umbilical artery
  • At 15 minutes, 2 hours, 12 hours, and 24 hours after birth from the dorsal metatarsal artery
• Blood samples were analyzed for:
  • Blood gas parameters (including pH, partial pressures of oxygen and carbon dioxide, oxygen saturation, lactate levels)
  • Hematological variables (such as sodium, potassium, ionized calcium, hematocrit)
  • Biochemical parameters (urea, creatinine, glucose, total plasma proteins, globulins, albumin)
• Apgar scores—a quick evaluation of newborn viability—were recorded at:
  • Birth (T0)
  • 5 minutes
  • 15 minutes

Key Findings

• Blood Gas Analysis:
  • At birth (T0), foals showed:
    • Lower pH (more acidic blood)
    • Lower arterial oxygen partial pressure (PaO2)
    • Lower arterial oxygen saturation and content
  • Over the next 24 hours, these oxygen-related parameters progressively increased, indicating improving blood oxygenation.
  • In contrast, parameters related to carbon dioxide and metabolic stress:
    • Partial pressure of arterial carbon dioxide (PaCO2)
    • Total arterial carbon dioxide (TCO2)
    • Arterial L-lactate concentration (indicator of anaerobic metabolism)

    were highest at birth and decreased steadily over time, suggesting resolution of initial birth-related respiratory and metabolic stress.

• Hematological and Biochemical Variables:
  • Electrolytes and waste product markers (sodium, potassium, ionized calcium, urea, creatinine) and hematocrit were elevated at birth but decreased by 24 hours.
  • Glucose, total plasma proteins, and globulins started low at birth and increased over the first day, reflecting metabolic adaptation and possible colostrum intake.
  • Plasma albumin levels remained relatively stable throughout.
• Apgar Scores:
  • No significant differences were observed in Apgar scores at birth, 5, and 15 minutes, indicating overall good immediate viability in the foals studied.

Conclusions and Implications

• The study provides detailed reference values for oxygenation, blood chemistry, and hematology in healthy Mangalarga Marchador foals during the critical first 24 hours of life.
• These baseline data can assist veterinarians and breeders in:
  • Monitoring neonatal foal health
  • Recognizing early deviations from normal values
  • Identifying compromised or at-risk foals promptly
  • Facilitating timely therapeutic interventions to improve survival and outcomes
• Improved understanding of neonatal physiology in this specific breed also supports tailored care for Mangalarga Marchador foals rather than relying solely on data from other horse breeds.