Protein-losing nephropathy is an inherited disorder of the kidneys affecting dogs. In healthy dogs, protein is not present in the urine, but in dogs affected with protein-losing nephropathy there is a defect that allows protein from the blood to be filtered by the kidneys and lost in the urine. Dogs typically present in middle-age with non-specific signs such as vomiting, diarrhea, and weight loss in addition to increased thirst and more frequent urination. If drinking excessively, some dogs may also inappropriately urinate in the house or in a crate. Occasionally affected dogs will also have edema and/or fluid accumulation in the abdomen or lungs. Dogs are typically euthanized within a few months after diagnosis due to the poor prognosis.
Genetic testing of the KIRREL2 and NPHS1 genes will reliably determine whether a dog is a genetic Carrier of protein-losing nephropathy. Protein-losing nephropathy is inherited in a complex manner in dogs. If a dog inherits two copies of each of the mutations, the dog has a high risk of developing protein-losing nephropathy. Dogs that inherit any other combination of mutations in KIRREL2 and NPHS1 are at an unknown risk. Reliable genetic testing is important for determining breeding practices. In order to eliminate this Mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Dogs that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
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Littman MP, Wiley CA, Raducha MG, Henthorn PS. Glomerulopathy and mutations in NPHS1 and KIRREL2 in soft-coated Wheaten Terrier dogs. Mamm Genome. 2013 Apr;24(3-4):119-26.
Vaden S, Giger U, Spaulding K, Sellon R, Littman M, Harris T, Afrouzian M, Jennette J, Williams D, VanCamp S. Inheritance of protein-losing enteropathy and nephropathy of Soft Coated Wheaten Terriers. J Vet Intern Med. 2000 16:352