Traumatic diaphragmatic hernia (TDH) of cats develops most often as a result of vehicular or other blunt abdominal trauma. Inability to inflate the lungs is usually the result of abdominal organs moving into the thoracic cavity. Pleural fluid accumulation from hemorrhage may also occur. This retrospective study examined the factors associated with mortality after surgical repair of TDH in 34 cats. Twelve of the cats were hit by cars, two cats were injured by dog bites, and two cats had recurrence of a TDH that had previously been repaired. The cause of trauma was unknown in the other 18 cats, but history or clinical findings usually suggested trauma. Of the 34 cats studied, six died or were euthanized within 2 days of surgery. The cats included in the study were 3 months to 14 years of age. Cats that died were older (7± 5.59 years; median, 7.5 years) than those that survived (2.9± 2.91 years; median, 1.75 years).

Mortality was greater in cats that had concurrent injuries identified on physical examination, radiography, or surgery. Three of the 28 cats that survived had concurrent injuries, whereas five of the six that died or were euthanized had concurrent injuries; the sixth cat had cardiomyopathy. The cats that did not survive also had significantly lower respiratory rates than those that did.

Postoperative acute cardiac or respiratory arrest was reported in 5 of the 34 cats within 48 hours of surgery. Three of the cats that died had cardiac arrest. Reexpansion pulmonary edema (REPE) was confirmed as the cause of death in one cat. REPE has previously been reported in cats after repair of TDH. Gradual reexpansion of the lungs is recommended to prevent this disorder. REPE was not confirmed in two of the cats that died with respiratory distress because radiographs and necropsies were not performed. One cat was euthanized after development of septicemia from intestinal necrosis. A portion of the small intestine had become trapped in an inguinal hernia and was reduced and resected at the time of TDH repair. Follow-up was available for 14 of the 28 surviving cats. No clinical abnormalities were seen in 10 of the 14 cats. One cat was reported to breathe heavily after strenuous exercise, one cat was euthanized 7 months after surgery because of urinary incontinence, one cat was found dead outdoors 3 years after surgery and necropsy was not done, and one cat died 8 months after surgery from chronic nasal hemorrhage of unknown origin.

Traumatic diaphragmatic hernia in cats: 34 cases (1991-2001). Schmiedt CW, Tobias KM, Stevenson MA. JAVMA 222: 1237-1240, 2003.