Diaphragmatic hernia is a defect or hole in the diaphragm that allows the abdominal contents to move into the chest cavity. Treatment is usually surgical.
This is a photo of a peritoneopericardial diaphragmatic hernia in a cat. The photo was taken during necropsy from the right side of the cat. To the left is the abdomen, where part of the liver and the gall bladder can be seen. The diaphragm is in the middle. To the right is the thorax. The largest object seen in the thorax is the rest of the liver. Just to the right of that is the heart. The liver was connected to itself through a small hole in the diaphragm (not seen).