The invention relates to a computer tomography apparatus for examining a body part of a large animal, comprising a computer tomography (CT) device and a platform on which the CT device is mounted. The CT device has an annular gantry and a CT table to accommodate a body part of a large animal to be examined. The gantry is immovable relative to the platform. Relative to the platform and to the gantry the CT table is horizontally movably connected to the gantry and/or the platform in such a way that the CT table can be moved into a central opening in the annular gantry. The computer tomography apparatus further comprises a positioning device which is connected to the platform and is designed to position the platform having the mounted CT device relative to a supporting surface for a large animal. The positioning device is designed to position the platform having the mounted CT device in an operational state in such a way that during a relative movement with respect to the gantry the CT table remains stationary relative to the supporting surface.