Cystinuria (Newfoundland Type)

General Information: Cystinuria (Newfoundland Type) is an inherited kidney disorder affecting breeds such as Newfoundlands, Landseer Newfoundlands, and Newfypoos. The condition is caused by a mutation in the SLC3A1 gene, which plays a crucial role in the kidneys' ability to reabsorb the amino acid cystine from the urine. In normal conditions, kidneys reabsorb cystine, allowing only small amounts to pass into the urine. However, dogs with mutations in both copies of the SLC3A1 gene fail to reabsorb cystine, leading to high concentrations in the urine. This excess cystine can form crystals or stones, which may block the ureters or urethra, hindering normal urine flow. Affected dogs can have cystine detected in their urine as early as two days old, though symptoms such as difficulty urinating, frequent urination in small volumes, and blood in the urine typically appear between 6 to 8 months of age in males and later in females. The risk of urinary obstruction is higher in males due to anatomical differences. If left untreated, cystinuria can lead to recurrent urinary tract infections, kidney failure, and even death, making early diagnosis and management critical for maintaining the affected dogs' quality of life.

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 for the SLC3A1 gene is crucial for identifying carriers of the mutation responsible for Cystinuria (Newfoundland Type) in dogs. This condition is inherited in an autosomal recessive manner, meaning that a dog must inherit two copies of the mutated gene, one from each parent, to develop the disease. Carrier dogs, which have only one copy of the mutation, typically do not show symptoms but can pass the mutation to their offspring. When two carriers are bred, each puppy has a 25% chance of developing cystinuria and a 50% chance of being a carrier. Reliable genetic testing is essential for responsible breeding practices to avoid mating two carriers, thereby reducing the risk of producing puppies with cystinuria. By identifying carriers and making informed breeding decisions, breeders can help eliminate this disorder from dog populations, promoting healthier and more resilient future generations. It is also important to consider that while genetic testing for the SLC3A1 mutation reduces the risk of cystinuria, other genetic or environmental factors may still influence similar conditions, necessitating comprehensive genetic screening and careful management.