Xanthinuria, Type II (Cavalier King Charles Spaniel Type)

General Information: Xanthinuria, Type II (Cavalier King Charles Spaniel Type) is an inherited disorder in dogs characterized by the accumulation of xanthine, a metabolic byproduct, in the urine. This condition results from a genetic mutation that affects the normal breakdown of purines, leading to elevated levels of xanthine, which is insoluble and can form urinary stones. Dogs with two copies of the associated gene mutation are predisposed to this condition, which can manifest at any age. Symptoms include frequent urination, blood in the urine, straining to urinate, loss of appetite, lethargy, weakness, vomiting, and pain. Urinary stones can cause urinary tract infections or blockages, particularly in males due to anatomical differences, potentially leading to serious kidney damage. While not all dogs with the mutation will show symptoms, they will excrete increased xanthine in their urine, and feeding a specialized diet may help prevent stone formation.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing of the specific gene associated with Xanthinuria, Type II (Cavalier King Charles Spaniel Type) can determine if a dog is a carrier of this condition. This disorder is inherited in an Autosomal Recessive manner, meaning that dogs must inherit two copies of the mutated gene, one from each parent, to develop the disease. Carrier dogs, possessing only one copy of the mutation, typically do not show symptoms but can pass the gene to their offspring. When two carriers are bred, each pup has a 25% chance of developing the disease and a 50% chance of being a carrier. Reliable genetic testing is crucial for informed breeding practices to eliminate this mutation from breeding lines, and breeding two carriers together is not recommended to avoid producing affected pups. Dogs that are not carriers have no increased risk of having affected offspring.