34th Annual Scientific Meeting proceedings

Objective: The aim of this retrospective study was to compare frontal sinus, nasal cavity and skull conformation in brachycephalic, mesocephalic and dolichocephalic dogs using MRI examination.

Methods: Records from dogs that had a MRI examination to document neurologic brain diseases were reviewed. Dogs with pre-existing lesions or defects of the nasal cavities and frontal sinuses were excluded. Measurements collected included the length and width of the whole head, nasal cavities, frontal sinuses, nasal turbinates and nasal septum. Ratios from these parameters were calculated to statistically compare between groups.

Results: 147 dogs were included in this study:  65 being brachycephalic, 78 mesocephalic, and 4 dolichocephalic. 32% of brachycephalic dogs showed an agenesia of the frontal sinuses versus 21% of small or mini-breed mesocephalic dogs. In brachycephalic dogs, frontal sinuses showed a more rostral, vertical and lateral position compared to the other groups. 78% of brachycephalic dogs showed a nasal septum deviation versus 44% of mesocephalic dogs. 24% of brachycephalic dogs showed a verticalisation of the frontal sinus versus 6% of the mesocephalic ones. The nasal turbinate distribution into the nasal cavities was similar in brachycephalic and mesocephalic dogs, but correlated to the length of the head.

Conclusion: Anatomical abnormalities were significantly more numerous and severe in brachycephalic dogs and in mesocephalic small and mini-breed dogs, with major differences in frontal sinuses conformation. Three-dimensional imaging examination is recommended as part of the surgical planning before any naso-sinusal procedure in such breed dogs.