Abstract: | Two similar cytopathic agents were recovered from the throat and rectal swab specimens of an immature dog with upper respiratory tract disease. The reference isolate, 14-72R, was shown to be a member of the reovirus group by its physicochemical properties, cytopathic effects in cell cultures, and appearance when examined in the electron microscope. Both isolates hemagglutinated human type O erythrocytes and antigenically were closely related to reovirus type 2. The affected pup had an increase in antibody titer to reovirus types 2 and 3. The latter findings provide evidence for possible heterotypic antibody responses in dogs to reovirus infection. |