Five adult cheetahs (Acinonyx jubatus) from an Austrian zoo demonstrated identical clinical symptoms within a period of 2 yr: progressive hind limb ataxia, loss of proprioception, and eventual recumbency. The progress of the disease could not be influenced by drug therapy. Hematologic, blood chemistry, and cerebrospinal fluid values were within normal ranges. Plain radiographs and contrast myelography were unremarkable. Following euthanasia, histologic examinations revealed a massive demyelination of the spinal cord in all five cheetahs. The lesions were most predominant in the medullary white matter from T6 to L3. The specific cause of this degenerative myelopathy could not be identified. Similar syndromes have been seen in other species. Various possible causes, such as vitamin B-12 or copper deficiency or organophosphate poisoning, and a possible genetic basis for this disorder are discussed.