Authors: Alberghina Daniela, Statelli Alessandra, Monteverde Vincenzo, Vazzana Irene, Cascone Giuseppe, Panzera Michele
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Establishing baseline reference ranges for donkey serum cortisol has proven challenging, with substantially fewer datasets available compared to horses; Alberghina and colleagues addressed this gap by measuring cortisol via chemo-luminescent assay in 97 healthy donkeys and establishing a median baseline of 5.64 µg/dL (reference interval 3.40–10.54 µg/dL). Pregnancy significantly altered the endocrine picture, with pregnant donkeys in their final trimester exhibiting notably elevated cortisol concentrations compared to non-pregnant adults, alongside distinctive immune correlations including stronger associations with monocyte counts (r = 0.79) and an inverse relationship with neutrophil-to-lymphocyte ratio. Within adult non-pregnant females, cortisol correlated moderately with monocyte percentages and triglyceride levels, suggesting age-dependent modulatory effects on immune and metabolic function. For equine professionals, these findings underscore that physiological status—particularly late pregnancy—substantially influences cortisol interpretation in donkeys, and clinicians should account for age and reproductive state when assessing stress biomarkers or investigating metabolic or immune abnormalities. Whilst these reference values provide essential baseline data for donkey practitioners, the relatively small cohort and limited sex/breed diversity indicate that further validation across broader populations would strengthen their clinical utility.
Read the full abstract on PubMed
Practical Takeaways
- •Veterinarians interpreting donkey cortisol values should use species-specific reference ranges (3.40–10.54 µg/dL) rather than equine standards, as donkey physiology differs
- •Pregnancy status significantly affects cortisol levels in donkeys; baseline cortisol interpretation must account for reproductive stage to avoid misdiagnosis of stress or disease
- •Cortisol changes in pregnant donkeys correlate with immune cell populations, suggesting pregnancy-related immunological shifts that may affect clinical decision-making regarding treatment timing
Key Findings
- •Median serum cortisol in healthy donkeys was 5.64 µg/dL (2.5th–97.5th percentiles: 3.40–10.54 µg/dL)
- •Pregnant donkeys (9th–11th months) showed significantly higher cortisol levels than adult non-pregnant females (p < 0.05)
- •In adult females, cortisol correlated with monocytes (r = 0.37, p < 0.01) and triglycerides (r = 0.30, p < 0.05)
- •In pregnant donkeys, cortisol showed strong correlations with monocytes (r = 0.79, p < 0.01), basophils (r = 0.6, p < 0.05), and inverse correlation with neutrophil/lymphocyte ratio (r = −0.63, p < 0.05)