Xanthine urolithiasis and asymptomatic xanthinuria have been diagnosed in Cavalier King Charles spaniel dogs suggesting that primary xanthinuria may be a breed-related disorder, although its prevalence remains unclear. The hypothesis of this study was that asymptomatic xanthinuria is common in Cavalier King Charles spaniel dogs.


Free catch urine samples were collected from 35 client-owned Cavalier King Charles spaniel dogs and from 24 dogs of other breeds. The purine metabolites were measured by high-performance liquid chromatography. The urine ratios of xanthine/creatinine and hypoxanthine/creatinine were calculated and compared between the two groups of dogs.


The urine concentrations of purine metabolites were not significantly different between the two groups and were very low in both. The urine concentrations of xanthine in all 35 Cavalier King Charles spaniel were markedly lower than in the previously reported case of xanthine urolithiasis in a UK Cavalier King Charles spaniel dog.

Clinical Significance

Asymptomatic xanthinuria was not detected in this UK Cavalier King Charles spaniel population. This data may be used as a reference for urinary purine metabolite concentrations in the dog.