Disc herniation is one of the most common pathologies of the vertebral column in dogs. The aim of this study was to develop a geographical information system (GIS)-based vertebral canal (VC) map useful for spatial evaluation of extruded disc herniation (EDH) in dogs. ArcGIS® was used to create two-dimensional and three-dimensional maps, in which the VC surface is divided into polygons by lines representing latitude and longitude. Actual locations and directions of the herniated disc material were assessed by a series of 142 computer tomographies of dogs collected between 2005 and 2013. Most EDHs were located on the cervical and transitional regions (thoraco-lumbar and lumbo-sacral) and shown at the level of the ventro- cranial and ventro-central polygons created. Choropleth maps, highlighting the distribution and the location/direction patterns of the EDHs throughout the VC, were produced based on the frequency of the ailment. GIS proved to be a valuable tool in analysing EDH in dogs. Further studies are required for biomechanical analysis of EDH patterns.