Fifty six dogs diagnosed with intervertebral disk disease between January 1999 and August 2001 were reviewed to characterize signalments and prognosis. Seventy-five percent was chondrodystrophoid breeds (42 dogs). Mean age was 5.1$pm$3.0 year-old and fifty-four percent had acute onset. Interspaces between eleventh thoracic vertebrae and fourth lumbar vertebrae were affected most commonly. Success rate of conservative treatment to dogs with paresis was 83% and that of operation to dogs with paralysis was 67%. Six dogs were recurred and 50% of them had recovered again. There was significant correlation between success rate of treatment and the degree of clinical signs but there was no significant correlation between success rate of treatment and rate of onset, status of clinical signs, duration of clinical signs.