Genetic predisposition to purine uroliths in Dalmatian dogs.

Homozygosity for a defective recessive gene results in all Dalmatians having elevated concentrations of urine uric acid and predisposes them to formation of purine uroliths. Why some animals form uroliths and others do not is not known. In a pilot breeding experiment, the incidence of sensorineural deafness among backcrossed, high urine uric acid Dalmatians was significantly higher (probability less than 0.05) than among low urine uric acid siblings. Urine uric acid values for Dalmatians reported in the literature are not likely to be comparable, because uric acid appears to be more likely to precipitate in Dalmatian urine than in the urine of other dogs and man. Heating, alkalinization, and thorough mixing are required whenever specimens are transferred from one container to another or an aliquot is removed for assay.