Rabies is a zoonotic disease caused by the rabies virus. While the salivary glands are
important as exit and propagation sites for the rabies virus, the mechanisms of rabies
excretion remain unclear. Here, we investigated the histopathology of the salivary glands
of rabid dogs and analyzed the mechanism of excretion into the oral cavity. Mandibular and
parotid glands of 22 rabid dogs and three control dogs were used. Mild to moderate
non-suppurative sialadenitis was observed in the mandibular glands of 19 of the 22 dogs,
characterized by loss of acinar epithelium and infiltration by lymphoplasmacytic cells.
Viral antigens were detected in the mucous acinar epithelium, ganglion neurons and
myoepithelium. Acinar epithelium and lymphocytes were positive for anti-caspase-3
antibodies and TUNEL staining. In contrast, no notable findings were observed in the
ductal epithelial cells and serous demilune. In the parotid gland, the acinar cells,
myoepithelium and ductal epithelium all tested negative. These findings confirmed the path
through which the rabies virus descends along the facial nerve after proliferation in the
brain to reach the ganglion neurons of the mandibular gland, subsequently traveling to the
acinar epithelium via the salivary gland myoepithelium. Furthermore, the observation that
nerve endings passing through the myoepithelium were absent from the ductal system
suggested that viral proliferation and cytotoxicity could not occur there, ensuring that
secretions containing the virus are efficiently excreted into the oral cavity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.