The vacuum phenomenon was identified in the spine of 3 dogs by computed tomography. Gas from the vacuum phenomenon was clearly present in the disc space in 2 dogs. In the other the disc space was collapsed, and the gas was in the caudal vertebral endplate. In humans, gas accumulation in the intervertebral disc caused by the vacuum phenomenon seen on computed tomography spinal images is a sign of degenerative disc disease rather than infection. It may also be seen in the apophyseal joints and in the vertebral canal associated with the vacuum phenomenon in the disc or apophyseal joints. The recognition of the vacuum phenomenon in the spine in veterinary patients will likely become more important as computed tomography imaging becomes more common with the increased availability of this imaging procedure.