Hematology and clinical chemistry in mule foals from birth to two months of age: A preliminary study.
Authors: Vernaccini Matilde, Bindi Francesca, Bonelli Francesca, Nocera Irene, Sgorbini Micaela
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Hematological and Biochemical Reference Ranges in Mule Foals Understanding normal laboratory values in neonatal and young stock is essential for veterinary practitioners, yet mules—common working and sport animals—have received minimal scientific attention in this regard. This preliminary study addressed a significant gap by prospectively sampling blood from seven healthy mule foals at birth (pre-colostrum), 24 hours, 48 hours, and weekly thereafter through eight weeks of life, tracking age-related changes in haematological and biochemical parameters using appropriate statistical analysis. The researchers observed dynamic shifts across multiple parameters: red blood cell indices (RBC count, packed cell volume and haemoglobin) declined between 24 hours and one week; mean corpuscular volume and mean corpuscular haemoglobin fell throughout the first month; white blood cell counts rose markedly during the first week; and metabolic markers including aspartate aminotransferase, glucose, and lactate showed characteristic early-life fluctuations, whilst electrolytes remained relatively stable. Importantly, several mule foal values proved intermediate to, or distinctly different from, established equine and donkey reference ranges, suggesting that applying adult or even species-specific foal ranges to mule neonates could lead to misinterpretation and unnecessary intervention. Whilst the small cohort size necessitates caution, these findings support the need for dedicated reference ranges in mule foals and highlight the practical value of establishing age-matched baselines for accurate clinical assessment in this population.
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Practical Takeaways
- •Mule foal reference ranges cannot be assumed to match those of horses or donkeys; age-specific reference ranges are needed for accurate clinical interpretation
- •Physiological changes occur rapidly in the first week of life (RBC, hemoglobin, WBC), requiring caution when interpreting bloodwork in newborn mule foals
- •Laboratory parameters in mule foals may differ from both parent species, necessitating dedicated reference ranges for this hybrid species in clinical practice
Key Findings
- •Red blood cell count, packed cell volume, and hemoglobin decreased from 24 hours to one week of age in mule foals
- •Mean corpuscular volume and mean corpuscular hemoglobin decreased over the first month of life
- •White blood cells increased from birth to seven days of life
- •Several hematological and biochemical parameters in mule foals were intermediate, lower, or higher than values in equine or donkey foals