Xanthinuria type II

Hereditary xanthinuria is a genetic disorder that results in elevated xanthine, a metabolic secondary product of purine metabolism, in the urine. Because of its low solubility, the increased xanthine concentration leads to a high risk for the formation of xanthine crystals and urinary stones, as well as secondary renal injury.
Typical symptoms are straining to urinate, frequent urination, urgency with urination, blood in the urine, life-threatening urinary obstructions and also kidney disease is a possible result of the disease. The age at first signs is very variable and ranges from several weeks to several years of age.

Several genetic variants have been identified to cause xanthinuria in different dog breeds. Variants of the xanthine dehydrogenase (XDH) gene are classified as xanthinuria type 1 and variants of the molybdenum cofactor sulfurase (MOCOS) gene as xanthinuria type 2, whereby both genes encode for enzymes of the purine metabolism pathway.
The genetic tests helps to identify and treat affected dogs before they form stones. Low-purine diet and increased fluid intake can reduce the risk for stone formation. Furthermore, the test helps to identify asymptomatic carriers of the disease and enables to choose the appropriate breeding partners.