ABSTRACT
The objective of this study was to evaluate the feasibility and accuracy of estimating the smallest amount of abdominal free gas detectible in a large population of beagles by ultrasonography. Healthy dogs were randomly divided into three groups: group A that received 0.1 mL of air injected into the peritoneal cavity, group B that received 0.2 mL of air injected into the peritoneal cavity, and group C that received 0.5 mL of intraperitoneal air. Randomly, some dogs in each group did not receive air injection for the negative control. All ultrasonographic procedures were performed by individuals blinded to group assignments and the presence of intraperitoneal air. The minimum volume of consistently detectable air with good accuracy and reliability was 0.2 mL. Results of the study demonstrated that the enhanced peritoneal stripe sign (EPSS) can verify cases of pneumoperitoneum if more than 0.2 mL of intra-abdominal free gas is present The EPSS is a reliable and specific ultrasonographic characteristic for diagnosing pneumoperitoneum in dogs.