For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.
At risk dogs are highly likely to show signs of this disease in their lifetime.
Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.
Familial Nephropathy, also known as autosomal recessive hereditary nephropathy (ARHN), is an inherited kidney disorder. The disorder is caused by defective type IV collagen in the basal lamina of the glomerular capillary walls. This collagen defect results in proteinuria beginning between 5 to 8 months of age, which then leads to early-onset renal failure and premature death by 10 to 27 months of age. Clinical signs associated with renal failure include excessive drinking and frequent urination. Other possible clinical signs include poor growth, vomiting, diarrhea, weight loss, lethargy, halitosis (bad breath), and poor coat quality. Confirmation of the disorder can be made through blood and urine testing. Abdominal ultrasound may also be used for diagnostics. Definitive diagnosis is made by kidney biopsy and appropriate pathologic evaluations.
There is no effective treatment available for FN. Therapy is limited to symptomatic treatments and general supportive care. Symptomatic treatment typically consists of medication reducing proteinuria and feeding a specialized diet. Due to the early onset and progressive nature of the disorder, the prognosis is considered poor and death often occurs at a young age.
There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.
This disorder is autosomal recessive, meaning two copies of the variant are needed for a dog to be at an elevated risk for being diagnosed with the condition. A carrier dog with one copy of the Familial Nephropathy, (Discovered in the English Springer Spaniel) variant can be safely bred with a clear dog with no copies of the Familial Nephropathy, (Discovered in the English Springer Spaniel) variant. About half of the puppies will have one copy (carriers) and half will have no copies of the variant. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disorder signs similar to the ones associated with this Familial Nephropathy variant could develop due to a different genetic or clinical cause.
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Nowend, K. L., Starr-Moss, A. N., Lees, G. E., Berridge, B. R., Clubb, F. J., Kashtan, C. E., … Murphy, K. E. (2012). Characterization of the Genetic Basis for Autosomal Recessive Hereditary Nephropathy in the English Springer Spaniel. Journal of Veterinary Internal Medicine, 26(2), 294–301. View the article