Bomed Veternary Clinic, Sofia
Pneumoperitoneum refers to accumulation of gas within abdominal cavity, resulting from a perforated hollow viscus, penetrating wounds or bacterial peritonitis. Emergency condition of massive pneumoperitoneum compromise cardiorespiratory function, known as pneumoperitoneum, has been reported in humans. In veterinary medicine, there are also a few similar cases.
A 10 years old British shorthair spayed female cat Tara (2.8 kg) was presented with a remarkable abdominal distention. Three months ago, the cat was operated because of suspected alimentary lymphoma. A part of small intestine and caecum was removed. Histology confirmed large cell lymphoma. Tara was started on chlorambucil and prednisolone protocol. Regular control examinations showed only decreased appetite and one or two times weekly vomiting. The last examination was two days before pneumoperitoneum, and ultrasonography was unremarkable.
At the time of admission, the cat was in good condition except respiratory distress, with huge ballooned, tympanic abdomen. Abdominal US showed only gas. Emergency needle abdominocentesis was performed, and about 300 ml air was aspirated. Than was performed X-ray. The abdominal radiograph showed distended by air abdominal wall, compressed viscus, displaced to thoracic cavity diaphragm. There was no evidence for free fluid in abdominal cavity. Subcutaneously was small amount of air, leaked after the needle aspiration. Second abdominocentesis was performed, and about 400 ml air was aspirated. The aspirated gas had no odor or admixtures.
On the next day, the cat was rehydrated, and a laparotomy was performed. Mild peritonitis was found with a small almond of yellowish ascites. The small intestines were empty, in the large intestines there were some faeces. The site of previously enter anastomosis was perfect. There was no evidence of leaking from the gut or any visible evidence of recurrence of lymphoma. A 6-8 mm perforation was found at the gastric fundus. The stomach, liver margin and omentum were mildly adhered. Other portions of stomach wall looked visually and palpably normal. After blunt dissection of the adhered liver and omentum, the gastric perforation was closed with interrupted sutures. Materials from stomach wall for cytology and from free fluid for microbiology were taken. Abdominal cavity was flushed with 0.9% warm saline and closed in a routine manner. Cytology did not show atypical cells, or any suspect for alimentary lymphoma. Microbiology was unremarkable.
Reported common causes for pneumoperitoneum in small animals include abdominal surgery, gastrointestinal perforation and bacterial peritonitis. In cats pneumoperitoneum also has been reported as complication after endoscopic biopsy or gastrostomy tube replacement. Most of these cases have not shown severe abdominal distention, necessitating emergency decompression.
The exact cause of gastric perforation in this cat is unknown. We suspect local weakness of gastric wall due to iatrogenic factors. Chlorambucil or prednisolone, or combination of these two medicaments may cause damage of mucosa and weakness in the walls of GI tract.
Necessity of therapeutic emergency abdominocentesis due to spontaneous pneumoperitoneum in cats has been emphasized only in few previous reports.