Comparison of Donkey, Pony, and Horse Dorsal Profiles and Head Shapes Using Geometric Morphometrics.
Authors: Maśko Małgorzata, Wierzbicka Małgorzata, Zdrojkowski Łukasz, Jasiński Tomasz, Sikorska Urszula, Pawliński Bartosz, Domino Małgorzata
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Understanding morphological differences between equine species is essential for developing species-appropriate welfare assessments and husbandry standards, yet donkeys are frequently evaluated using frameworks designed for horses despite their distinct anatomical characteristics. Researchers applied geometric morphometrics—a sophisticated shape-analysis technique using photographic landmarks and sliding semilandmarks—to quantify dorsal (back) profiles and head shapes across matched groups of 14 donkeys, 14 ponies, and 14 horses, with the first three principal components accounting for 81.52% and 65.89% of total variation respectively. Donkey and horse morphology differed significantly across both parameters (p < 0.0001), whereas donkeys and ponies showed statistically similar dorsal profiles and head shapes; notably, whilst ponies and horses differed substantially in size, their actual shapes were comparable, suggesting ponies represent scaled-down horses rather than a morphologically distinct type. These findings have direct implications for practitioners developing or adapting welfare assessment tools, saddle-fitting protocols, and bitless bridle designs—applying equine standards to donkeys without accounting for their distinct back contours and head geometry could result in compromised comfort and welfare. Farriers, veterinarians, and equine therapists should recognise that donkeys warrant species-specific assessment methodologies rather than simply adjusting horse-based protocols by size.
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Practical Takeaways
- •Donkeys have distinctly different body and head morphology from horses, meaning welfare assessment protocols and pain indicators designed for horses may not directly translate to donkeys
- •Ponies and horses share similar body shapes but differ in size, whereas donkeys represent a genuinely distinct morphotype requiring separate evaluation criteria
- •When adapting equine welfare or performance standards to donkeys, practitioners should account for these fundamental morphological differences to ensure fair and accurate assessment
Key Findings
- •Dorsal profiles and head shapes differed significantly between donkeys and horses (p < 0.0001) but not between donkeys and ponies (p > 0.05)
- •Principal component analysis explained 57.16% of dorsal profile variation and 44.77% of head shape variation in the first component
- •Ponies and horses differed in size but not in shape for both dorsal profiles and head shapes (p < 0.0001 vs p > 0.05)
- •Geometric morphometrics revealed morphological differences that should inform species-specific welfare assessment scales