CHARACTERISTICS OF URIC-ACID METABOLISM A ND THEIR CLINICAL ASPECTS IN DALMATIAN DOGS - REVIEW ARTICLE

Knowledge on the particular uric acid metabolism of Dalmatian dogs hav e been summarized in the framework of the results of recent research. After the general review of purin metabolism, pathophysiological chara cter and clinical consequences of hereditary anomalies have been revie wed that developed in Dalmatian dogs due to a mutation. According to t hat, the hepatic allantoin formation from uric acid has significantly decreased in Dalmatians as compared to other dog breeds which is cause d by the membrane-transport disturbance of hepatocytes. Due to the ano maly, only a small part of uric acid, produced in a quantity comparabl e to other dog breeds, is transported from the blood plasma into the h epatocytes where, on the other hand, the activity of uricase responsib le for the allantoin production is sufficient. That is the reason that the urate concentration of plasma is higher in Dalmatians than in oth er breeds. However, precipitation of uric acid, i.e. development of go ut does not occur because the uric acid secretion of renal tubuli is m uch higher than in other dog breeds and it prevents the development of hyperuricaemia at a dangerous level. However, significant uric acid e xcretion can be the source of urolithiasis caused by urates. After hav ing detailed the physiological and pathological relations, clinical fe atures, prevention and treatment of urate urolithiasis and ''bronze sy ndrome'' have been summarized. Clinical signs of urate urolithiasis ar e the same as other urolithiases. ''Bronze syndrome'' causes brownish- red, frequently itching swelling on the thoracolumbal region with disc olouring of the skin and of the hair. Prevention and treatment of both disorders includes a low purin (protein) diet, alkalization of the ur ine with daily supplementation of the diet with 0.5 to 1 g/10 kg of bo dy mass of sodium hydrogencarbonate, for decrease of uric acid formati on by a daily dose of 30 mg/kg of body mass of allopurinol (xantin-oxi dase inhibitor) and forced diuresis.