Mesenteric volvulus was diagnosed in 12 dogs over a nine-year period. Each case was presented with abdominal distension and shock. Haematochezia, which is frequently reported in association with mesenteric volvulus, was present in only two of the dogs. The diagnosis, which in all cases was based on radiography, was followed by immediate treatment for shock and surgical intervention whenever possible. In five of the 12 cases, the volvulus was treated successfully and these patients survived. This indicates that the prognosis for mesenteric volvulus might be better than is currently believed, and immediate laparotomy is recommended if mesenteric volvulus is suspected.