Parés-Casanova, P. M.; Bottini, I. & Tugnoli, C.

Studies related to the upper respiratory pathway asymmetries are still scarce in the veterinary literature. We present here a study of choanae asymmetries of a pure horses belonging to “Cavall Pirinenc Català” (Pyrenean Horse Breed). For this goal, the palates of 23 dry skulls with no apparent pathologies were photographed and evaluated using geometric morphometrics. On each photo, we identified and digitized a total of 26 points (subset of 2 mid-sagittal, 4 paired landmarks (discrete homologous points) and 10 semilandmarks (points on an outline determined by extrinsic criteria) per side on the choana. Both fluctuating and directional asymmetries appeared statistically significant, the latter accounting more than half of the total variation. The lateral bend observed in horse choanae may be due to the asymmetrically positioned nasal passages. So detected equine choana asymmetry must rather be considered functional, with no clinical implication and presents an important consideration when equine choanae shape.

KEY WORDS: Cavall Pirinenc Català; Nasal cavity; Nasal laterality; Pharynx, Oropharyngeal cavity; Upper airways.

PARÉS-CASANOVA, P. M.; BOTTINI, I. & TUGNOLI, C. Horse choanae are directionally asymmetric. Int. J. Morphol., 39(4):956-959, 2021.