Universitext Universitext

Abstract

A generalized decrease in serosal margin detail, consistent with abdominal effusion, steatitis, or peri-tonitis (Figure 2), is evident. The small intestines are diffusely dilated with gas, and the stomach is distended with a mixture of soft tissue or fluid opacity and gas. The large intestine is displaced and obscured by di-lated small intestinal segments, and no obvious large intestinal abnormalities are detected. Multiple, small, amorphous gas opacities along the ventral aspect of the abdominal wall overlying the ventral margin of the stomach are evident, most likely representing free ab-dominal air (pneumoperitoneum) or gas inclusions in the gastric wall due to gastric wall necrosis or extensive ulceration. Paralytic ileus was the top differential diagnosis for generalized, severely dilated intestinal loops. Mes-enteric torsion was considered unlikely because of concurrent gas distension of the stomach and because an even more severe degree of intestinal distension is usually observed in cases of mesenteric torsion. With no recent history of surgery and no history of blunt force trauma, bacterial septic enteritis or peritonitis was considered the most likely underlying cause of distension of the gastrointestinal track. Possible un-derlying causes of spontaneous pneumoperitoneum in this patient included gastrointestinal perforation or bacterial peritonitis. Treatment and Outcome Because of the suspicion of free peritoneal gas or gastric wall necrosis, exploratory laparotomy was immediately performed via a standard midline ap-proach. Extensive diffuse peritonitis was identified, and the stomach and small intestine were severely diffusely distended and discolored and lacked motil-ity. The beaver was euthanized because of the poor prognosis and anticipated difficulty of intensive medical care in this nondomestic patient. Necropsy revealed fibrin strands in the peritoneal cavity, uni-form gaseous distension of the gastrointestinal tract, extensive ulceration and erosion of the gastric mu-cosa, discoloration (dark red to gray) of the jejunum, and necrotizing colitis. Histologic examination identified surface bacteria associated with the gas-tric lesions, intralesional bacteria within the co-lon, acute diffuse fibrinous pneumonia, and acute diffuse periportal hepatitis and cholangitis. A final diagnosis of bacterial gastroenteritis with septice-mia was made. Comments