Studies on canine distemper infection by means of fluorescein-labeled antibody: II. The pathology and diagnosis of the naturally occurring disease in dogs and the antigenic nature of the inclusion body

Abstract

In examinations of dogs with natural canine distemper infection, specific viral antigen was found in the visceral and cutaneous tissues as well as in the brain, depending on the stage of the infection. Localization of viral antigen in cutaneous tissues and visceral organs is similar to that seen in experimentally infected ferrets. In the brain of the dogs, however, viral antigen in the form of fluorescent granules or oval masses was found in the cell bodies of the neurons and in their dendrites and axons; also in ependymal cells and astrocytes. Viral antigen was seen in the walls of blood vessels of the brain in dogs with or without central nervous system lesions. The fuchsinophilic distemper inclusions in urinary bladder mucosa cells stained by the Seller's method are found to be antigenic. However, the acidophilic inclusions seen after Shorr's Triple (S-3) stain may be but usually are not antigenic. For the rapid diagnosis of acute canine distemper infection in dogs, fluorescent antibody staining of cells in conjunctival smears is found to be simple and practical. A similar method can be applied to imprint smears of various organs in autopsied dogs for specific post-mortem diagnosis.