Radiographic and ultrasonographic findings of emphysematous cystitis in four nondiabetic female dogs.

The urinary bladder of four dogs with emphysematous cystitis was assessed radiographically. Ultrasonography was also performed using a 7.5-MHz microconvex probe in dorsal recumbency and in a standing position. Ultrasonographically there were bright echoes and reverberations typical of gas in all dogs. This was entrapped in the bladder wall as it appeared in the same location in recumbent and standing positions. Bladder size was reduced and bladder content was echogenic in all dogs. In only one out of the four dogs was a gas stripe seen in the bladder on radiographs. Proteus mirabilis was isolated from the urine of all patients. Diabetes was ruled out on the basis of urine and blood analysis. A small amount of gas can be difficult to detect on radiographs. Ultrasonography appears to be a more sensitive technique for detection of gas within the bladder at an early stage of emphysematous cystitis. Prevalence of emphysematous cystitis may be underestimated if only radiographs are made.