Segmental Megaesophagus Secondary to Extraluminal Esophageal Stenosis Caused by Transitional Seventh Cervical Vertebra and Supernumerary Ribs in a Goat.

A 4-year-old Nigerian Dwarf wether presented for chronic regurgitation and cervical swelling of three years duration. Physical examination revealed a large ventral cervical mass. The goat made repeated attempts to swallow and regurgitate, but the mass did not change significantly in size. Cervical radiographs revealed segmental esophageal dilation to the level of the thoracic inlet. CT revealed a transitional seventh cervical vertebra with fused right and left ribs, resulting in extramural esophageal compression and obstruction at the level of the thoracic inlet. This is the first report of a cervical rib causing megaesophagus in a goat.