Details about the disease
Normally, cystine is filtered in the kidney and reabsorbed within the tubules, resulting in little cystine in the urine. Dogs with cystinuria (defective transport of the amino acid cystine in the kidney tubules) do not properly reabsorb the cystine (and a few other amino acids) in the kidney tubules, causing the urine to contain abnormally high levels of cystine. Cystine is insoluble in neutral pH or acidic urine, so excess urinary cystine results in the formation of crystals, which in turn can lead to formation of cystine calculi (stones) in the kidney and/or the bladder. Dogs suffering from cystinuria suffer repeated urinary tract inflammations, and are at risk for urinary blockage, which can, if not treated promptly, lead to kidney failure, bladder rupture and death.
Clinical signs
The average age of onset of clinical signs attributable to cystinuria is about 4.8 years, but in Newfoundlands, signs appear as early as 6 months to 1 year, suggesting that Newfoundlands suffer from a more severe form of the disorder than other breeds.
How is it inherited?
The disease is described as an autosomal-recessive condition. This means that a dog must inherit two copies of an abnormal gene (one from its mother and one from its father) before its health is affected. A dog that inherits only one copy of the abnormal gene (from its mother or its father) will have no signs of the disease, but will be a carrier and may pass the gene on to any offspring.
Which laboratories we record and publish the results from?
To find out which laboratories The Kennel Club is able to record results from, and which laboratories will send results directly to The Kennel Club, please refer to our website.
Please be aware, The Kennel Club has a set of criteria that we request DNA testing laboratories to meet to enable us to record their results, helping to maintain and protect the integrity of results that appear on a dog’s record. We strongly advise that customers ensure their chosen laboratory is included on our list if they wish The Kennel Club to record and publish the results. Results from laboratories not included on this list will not be recorded.
Breeding advice and what your dog's results mean
If, once your dog is DNA tested, you would like to find out what their DNA test results mean, or how to select the right mate to avoid producing affected puppies, then please read our breeding advice and DNA testing information.
How to find out if a potential mate has been DNA tested
The Kennel Club’s Health Test Results Finder allows you to find the results of DNA tests carried out as part of The Kennel Club's official DNA testing schemes for any dog on The Kennel Club’s Breed Register.