Abstract
Background:
Computed tomography (CT) is the gold standard for diagnosing canine nasal diseases. However, it cannot easily detect minor abnormalities in inflammatory diseases because they are not accompanied by obvious morphological changes.
Aim:
The present study aimed to compare the differences in normal CT findings of turbinate structure and mucosa between breeds in order to establish criteria for CT diagnosis of inflammatory diseases of the nasal cavity.
Methods:
CT data from 77 dogs of five breeds without nasal diseases were retrospectively studied. The nasal air percentage, which reflects the volume of the nasal turbinate structure and mucosa, was measured. The nasal turbinate mucosa was measured for contrast enhancement reflecting blood flow. Measurements were performed in the ventral and ethmoid turbinate regions. Comparisons were made between breeds and sections.
Results:
The air percentage in the ventral and ethmoid turbinate regions was significantly different between breeds. Contrast enhancement was significantly different between breeds only in the ethmoid turbinate. Moreover, different breeds had different correlations between body weight, age, nose length, and air percentage.
Conclusion:
In this study, reference values for normal CT findings of the nasal structure and mucosa were obtained, taking into account the breed, measurement section, and patient factors. The results showed that the volume of the turbinate structure and contrast enhancement of nasal mucosa differed depending on the breed. The measured values also differed depending on the cross-sections and patient factors.

Key words: Computed tomography, Dog, Nasal inflammatory disease, Turbinate structure, Turbinate mucosa