Pneumoperitoneum in dogs and cats: 39 cases (1983-2002)

OBJECTIVE: To identify the most common causes of pneumoperitoneum in dogs and cats and determine history, clinical features, and outcome of affected animals. DESIGN: Retrospective study. ANIMALS: 31 dogs and 8 cats. PROCEDURES: Medical records were reviewed for signalment; history; abnormal physical, clinicopathologic, and radiographic findings; results of cytologic analysis and bacterial culture of abdominal fluid; gross and histologic findings at surgery or necropsy; and outcome. RESULTS: Pneumoperitoneum was classified as spontaneous in 25 animals and traumatic in 14. Causes of traumatic pneumoperitoneum included vehicular impact, gunshot wounds, abdominal dog bite wounds, and iatrogenic pneumothorax. Spontaneous pneumoperitoneum was caused by gastrointestinal tract perforation in 23 animals; underlying causes included neoplasia, nonsteroidal anti-inflammatory drug administration, and corticosteroid administration. Two animals developed spontaneous pneumoperitoneum after bladder rupture. Animals with spontaneous pneumoperitoneum were significantly older and had clinical signs of longer duration than those with traumatic pneumoperitoneum. Sixteen animals survived, including 15 of 23 animals that underwent surgery. Animals that survived had significantly higher serum albumin concentrations than did animals that died or were euthanatized. CONCLUSIONS AND CLINICAL RELEVANCE: Although pneumoperitoneum is most often attributable to perforation of a hollow viscus, other causes do exist. Early exploration is recommended for diagnosis and treatment of the underlying condition.