Hiatal hernia is a protrusion of abdominal contents through the esophageal hiatus of the diaphragm into the thorax. Nutritional osteoporosis may cause vertebral deformities such as lordosis and kyphoscoliosis. A five-month-old male cat with the history of constipation and dyschezia, lameness, vomiting and respiratory distress was referred to Small Animal Hospital, Faculty of Veterinary Medicine, University of Tehran. Routine physical examination and plain radiographs were indicated severe nutritional osteoporosis and kyphoscoliosis. The case was referred again due to abdominal distention and repeated vomiting two days later. Positive contrast radiographs showed sliding hiatal hernia and megaesophagus. Surgical correction of hiatal hernia by diaphragmatic hiatal reduction, esophagopexy and gastropexy after repositioning of the stomach and gastroesophageal junction was performed. The case was followed up for seven months. Survey radiographs showed no signs of recurrence.

It is assumed that kyphoscoliosis and lordosis due to nutritional osteoporosis may cause an increase in intraabdominal pressure and malpositoning of the cardia and fundus, which may lead to hiatal hernia. Veterinary practitioners should have an index of suspicion of hiatal hernia in severe osteoporotic cats with signs of vomiting and regurgitation.