This condition causes kidney and bladder stones composed of urate. In most dogs, uric acid is converted to allantoin, an inert substance that is then excreted in the urine. Dogs with HUU have defects in the pathway that converts uric acid to allantoin. As such, uric acid builds up, crystallizes and forms urate stones in the kidney and bladder. Uric acid is an intermediate of purine metabolism. While hyperuricemia in other species (including humans) can lead to painful conditions such as gout, dogs do not develop systemic signs of hyperuricemia.
What are the signs & symptoms that develop in affected dogs?
Affected dogs will show no clinical signs of disease in the early stages. As stones form, dogs will often urinate more frequently, urinate in inappropriate places, and possibly have blood in their urine. If a urinary obstruction forms, they are unable to urinate despite frequent straining. This is a medical emergency.
When do signs and symptoms develop?
Most dogs are adults before they show any signs of urinary issues (4-6 years on average).
How do vets diagnose this condition?
Urate stones are invisible on X-rays and must be diagnosed by a veterinarian via ultrasound or urine sediment analysis. If left undiagnosed, bladder stones can lead to urinary obstruction, which can be life-threatening.
How is this condition treated?
If caught early, it is responsive to dietary management. Surgical intervention is often required when stones or an obstruction forms.
What actions should I take if my dog is affected?
Closely monitoring your dog's urination habits, routine lab work, and following your veterinarian's nutritional advice are the best ways to keep your dog healthy.