[Pyonephrosis due to xanthine stones in a bitch treated with allopurinol]

A 2-year-old, neutered, crossbreed bitch was presented as an emergency with painful abdomen, fever and vomiting. The cause of the acute abdomen was a pyonephrosis of the left kidney, caused by four xanthine stones, which had blocked the ureter. After surgical removal of the heavily altered left kidney, the bitch recovered rapidly. Because of a leishmaniasis the bitch had been treated with allopurinol over an extended period, the xanthine stone formation is likely to have resulted from allopurinol usage. Because there were additionally small concrements in the right kidney, the medication was stopped. Subsequently, the dog has received a low purine diet, and the leishmaniasis titer and renal function have been monitored regularly.