Cystinuria is a genetic disorder affecting over 170 breeds of dogs. This disease causes uroliths (bladder or kidney stones) to form in the lower or upper urinary tract. Cystinuria has no permanent cure, but there are many ways to manage it [1].
Understanding the symptoms, causes, and treatments for cystine stones in dogs will help you provide the best care.
What Are Cystine Stones in Dogs?
Cystine is a naturally occurring amino acid found in many foods. Healthy dogs absorb cystine through the walls of the small intestine, circulate it through the body, and filter it through the kidneys [1].
Dogs with cystinuria have genetic mutations that prevent them from reabsorbing cystine and other amino acids, including lysine, arginine, and ornithine. These amino acids build up in the urine and may form bladder or kidney stones [2].
Cystinuria occurs in an estimated 1% to 3% of dogs in North America. Approximately 99% of affected dogs are male, and 1% are female [1].
Certain breeds have a higher risk of developing cystine stones, including [2].
- Staffordshire bull terrier
- Danish Swedish farmdog
- Chihuahua
- Shetland sheepdog
- French bulldog
- Mastiff
- Australian cattle dog
- Pitbull terrier
- Rottweiler
Symptoms of Cystine Bladder Stones in Dogs
Dogs are born with cystinuria but often don’t display symptoms unless cystine stones develop. Pet owners typically notice these signs [3]:
- Difficulty or pain when urinating
- More frequent urination
- Toileting in the house
- Bloody urine
In some cases, cystine stones block the urethra. Symptoms of urinary obstruction include a distended bladder, abdominal pain, lethargy, and vomiting [3].
A urethral blockage is a serious and potentially fatal medical emergency. Seek emergency veterinary care promptly if you suspect your dog has an obstruction [3].
Diagnosing Cystine Stones in Dogs
Veterinarians typically use urinalysis to detect cystine bladder stones in dogs. This test can reveal the presence of cystine crystals in the urine, though these formations aren’t continuously present [1].
Additionally, some dog breeds have genetic tests for cystinuria. These tests detect this condition before the dog develops symptoms [1].
Treatment for Cystine Stones
Cystinuria is an inherited metabolic error with no cure. However, there are several ways to manage this condition [1].
Veterinarians typically treat cystine stones in dogs by surgically removing or dissolving them. These stones often recur within six to 12 months [1].
Diet can help prevent the formation of uroliths. Owners should feed their dogs with a low-protein, alkalinizing prescription diet. This food has minimal amounts of amino acids that can build up in the urine. Dogs with cystinuria should also eat low-sodium foods [1].
Additionally, castration can resolve some types of androgen-dependent cystinuria in male dogs [1].
Keep Tabs on Your Dog’s Health With Petnox
The symptoms of cystinuria can creep up on you slowly. Even the most attentive pet owners can overlook subtle signs like their dog straining to urinate or having the occasional accident.
Catch cystine stones and other urinary conditions early with veterinary-grade urine test strips. Diagnox’s Petnox-10 lets you monitor your dog’s urinary health at home. The test measures 10 critical parameters, including blood, leukocytes, nitrites, pH, protein, and specific gravity. These measurements provide valuable insights into your pet’s urinary health and help you know when to seek veterinary care. Pick up a box today and start testing in minutes.
