Uric acid is among a variety of substances that can form crystals in your dog's bladder. If these crystals bunch together, they can form life-threatening stones with the potential to block the urethra. Uric acid crystals form stones known as urate uroliths. Since there's a hereditary component to the formation of these particular stones, ask your vet about a preventative diet if your dog is at risk.
Biochemicals called purines are found in meat. In humans and most canines, the liver converts purines such as uric acid into allantoin. Water-soluble allantoin easily exits the body through urine. Some dogs can't make that conversion in the liver, so the uric acid, which isn't very soluble, goes through the excretory system. Non-excreted uric acid crystals eventually clump together, creating stones.
While many breeds of dogs are prone to urinary crystals and stones, relatively few develop urate stones. Among them, Dalmatians are particularly susceptible, as are English bulldogs and the rare Russian terrier. Dogs born with liver shunts often suffer from this issue. Other than those with liver shunts, dogs forming uric acid crystals or stones have a genetic predisposition to do so. Uroliths form in male dogs far more often than in females.
If your dog suffers from urinary crystals or stones, you might notice blood in his urine. He might strain or appear uncomfortable when urinating. He might empty his bladder in small amounts rather than in one continuous stream. You might even notice some grit in his pee. If a stone obstructs his urethra, that's a veterinary emergency. Dogs can die within two to three days if they can't pee.
If your dog becomes obstructed, surgery might be necessary to remove stones from the urethra and bladder. Small stones might respond to flushing out via a urinary catheter. If you live near a veterinary facility that offers ultrasonic dissolution, it's a less invasive method of getting rid of stones if your dog isn't blocked. Ultrasonic waves break down the urate crystals and stones, which are then flushed out of the dog.
If you own a Dalmatian, you might prevent the formation of uric acid crystals and stones by feeding a low-protein, low-purine canned diet. Avoid liver and kidney dog foods, as these organ meats are high in purines. Your vet can prescribe a supplement that helps alkalize the urine. However, dogs with liver shunts shouldn't eat a low-protein diet, so your vet can recommend the right food for affected canines. Make sure your dog drinks plenty of water. You can add water to his canned food to get more fluids into him. The more water he drinks, the more likely he is to flush out uric acid crystals before they can clump and form stones.
By Jane Meggitt
PetMD: Urinary Tract Stones/Crystals Made Up of Uric Acid in Dogs
University of Minnesota Minnesota Urolith Center: Canine Urate Uroliths
VCA Animal Hospitals: Urate Bladder Stones in Dogs
Veterinary Partner: Uric Acid Stones and Urate Urolithiasis
Merck Veterinary Manual: Urolithiasis in Small Animals
About the Author
Jane Meggitt has been a writer for more than 20 years. In addition to reporting for a major newspaper chain, she has been published in "Horse News," "Suburban Classic," "Hoof Beats," "Equine Journal" and other publications. She has a Bachelor of Arts in English from New York University and an Associate of Arts from the American Academy of Dramatics Arts, New York City.