Contrast-Enhanced Computed Tomography Is Helpful for Characterizing Confirmed and Presumed Parotid Sialectasis in Rabbits

Abstract

Sialectasis, defined as a dilated salivary duct, is an uncommon salivary disease. There are limited published data regarding salivary gland disease or anatomy of the salivary system in rabbits. In dogs, computed tomography (CT) is described as the imaging modality of choice for salivary gland disease. Identification of the correct diseased gland and respective duct is required for surgical planning. There are currently no studies describing CT features of parotid sialectasis in rabbits. The aim of this single-center, retrospective, and descriptive study was to determine CT features of confirmed and suspected parotid sialectasis in rabbits. Conscious whole-body pre- and postcontrast CT studies from 21 rabbits presenting with dilated parotid ducts were reviewed. Diagnosis was confirmed in 10/21 patients, based on surgery (10/10) and histopathology (4/10), and presumed in 11/21 rabbits on the basis of imaging and clinical findings. A number of 19/21 rabbits had unilateral dilated parotid ducts (15/19 right-sided). All dilated parotid ducts were characterized by tubular (21/23) fluid attenuating, non-contrast-enhancing content (median 27 Hounsfield units) and soft tissue attenuating, thin, and regular contrast-enhancing rims. The 20/23 dilated parotid ducts extended from the parotid salivary gland or the mandibular ramus to the first maxillary premolar. Bacteriological culture was positive in 10/10 patients. Histopathological findings revealed concomitant sialadenitis in all four animals, associated with luminal bacterial colonies and foreign material in 2/4. Parotid sialectasis can therefore be associated with infectious sialadenitis. CT is helpful to precisely identify the affected salivary gland and also to differentiate sialectasis from more common dental-related abscesses in the rabbit species.