Comparative histological characteristics of the nasal cavity of Beagle dogs and rabbits

The nasal turbinate is a structurally complex organ essential for air conditioning and defense against inhaled toxicants. Despite its importance, standardized histological criteria for Beagle nasal turbinates have not been fully established, limiting the reproducibility and comparability of toxicological and pathological evaluations.

To characterize region-specific histological features of the Beagle nasal turbinates using anatomically defined anterior, middle, posterior, and olfactory regions.

Nasal cavities from five 8-month-old Beagle dogs and five 10-week-old New Zealand White rabbits were sampled at four anatomically defined transverse levels corresponding to the anterior (last upper incisor teeth), middle (upper canine teeth), posterior (third premolar teeth), and olfactory (fourth premolar teeth) regions, using reproducible dental and cranial landmarks. Hematoxylin and eosin and periodic acid-Schiff staining were performed to evaluate epithelial types, submucosal structures, and goblet cell distribution.

Gross transverse sections revealed clear anatomical differences between Beagles and rabbits, particularly in turbinate complexity. In the anterior region, Beagles were entirely lined by transitional epithelium, whereas rabbits had a mixed layer of stratified squamous epithelium. In the middle region, Beagles showed a broader distribution of respiratory epithelium with abundant goblet cells. In the posterior and olfactory regions, where olfactory epithelium was mainly distributed, Beagles showed more well-developed and significantly thicker olfactory epithelium compared to rabbits; mean difference 39.889 μm (95% CI, 11.079-68.698), p = 0.0138.

This study is the first to propose standardized, region-specific histological criteria for Beagle nasal turbinates, supported by quantitative analysis. By presenting its unique histological structures and traits, this study provides a reproducible reference framework for Beagle nasal cavity histology.