Effects of formalin on bladder urothelium.

Formalin instillation into canine bladders was followed by serial radiographic and histologic evaluation. A generalized slough of epithelial tissue was seen with the deposition of an amorphous substance. Telangiectasia resulted in moderate bleeding. No ureterovesical junction obstruction was seen and reflux occurring in 60 per cent of the animals reverted to normal. Correlation with clinical experience is made.