Here's why:
* Vertebrae Number is Species-Specific: The number of vertebrae is primarily determined by the species of animal, not the breed. All horses (Equus caballus) have a consistent number of vertebrae.
* Slight Variations: There may be minor variations in the number of vertebrae within a species, but these are rare and considered anomalies.
* Breed Focus on External Traits: Horse breeds are primarily defined by their external characteristics like size, coat color, and conformation, not internal skeletal variations.
Therefore, the number of vertebrae in a horse is consistent across all breeds.