Retrospective evaluations of medical cases can provide valuable information about the incidence of diseases in a population. In this study, archived files and necropsy findings of formalin-fixed, paraffin wax-embedded tissue specimens from 2646 dogs out of 20,117 necropsied dogs were found to be affected by a central nervous disorder over a period of 61 years from 1962 to 2022. In addition to various non-inflammatory diseases, 758 (28.6%) dogs were diagnosed with a non-suppurative inflammation of the central nervous system. In 397 (52.4%) of these cases, a specific etiology was identified, most commonly canine distemper and pseudorabies (also termed Aujeszky’s disease). Especially the pseudorabies cases cumulated in one distinct wave between the mid-1970s and 1990s, while canine distemper cases were found more evenly distributed with less clearly separated peaks, in the late 1960s and 1990s. This study shows the great value of long-term stored formalin- fixed, paraffin wax-embedded-tissue specimens for retrospective studies using different histologic stainings and immunohistochemistry for the detection of previously occurring disease outbreaks