Computed tomographic characteristics of normal salivary glands in dogs

BACKGROUND: Various salivary gland diseases diagnosed on computed tomography (CT) in dogs have been reported. However, no study described the size and CT attenuation value of normal salivary glands in dogs. AIM: This retrospective analytical study aimed to evaluate the size and attenuation value of the mandibular and zygomatic salivary glands on CT in dogs without cervical or head lesions. METHODS: The maximum cross-sectional area (MCSA) was measured in 96 dogs and attenuation value on non-contrast and postcontrast images were measured in 90 dogs. Dogs were divided into three groups based on body weight: group 1, ≤ 5.0 kg; group 2, 5.1–10.0 kg; and group 3, 10.1–15.0 kg. RESULTS: There were significant differences in MCSA for both glands among the three groups. There was no difference in MCSA between the left and right sides in both salivary glands. The MCSA for both salivary glands positively correlated with body weight (p < 0.001). There was a significant difference in the MCSA of the zygomatic gland between males and females (p = 0.02), but there was no significant difference in the mandibular gland. There was a significant difference in the attenuation value between the mandibular and zygomatic glands in non-contrast studies (p < 0.001), but there was no significant difference in postcontrast studies. CONCLUSION: This study established the reference for the size and attenuation value of the mandibular and zygomatic glands in dogs and provided background data for future CT evaluation of dogs with salivary gland diseases.