This definition appears rarely
Samples in periodicals archive:
the end product of purine metabolism or oxidation in the body in species other than dogs which metabolize uric acid to allantoin (except Dalmatians). Amounts of more than 1 mg/100 ml of uric acid in the blood are an indication of hepatic insufficiency. In birds excess amounts of uric acid and urates in tissue occur in visceral gout.
Humans do not possess the uricase enzyme that converts uric acid to allantoin. A genetically modified form of uricase called rasburicase has been produced to try to provide this, but it has severe risks and restrictions. It is currently only available in the US for cancer patients with high uric acid levels from chemotherapy.
The Dalmatian dog has a genetic defect in uric acid uptake by the liver and kidneys, resulting in decreased conversion to allantoin, so this breed excretes uric acid, and not allantoin.