Hereditary Nephritis (Samoyed) in Dogs

Hereditary nephritis affects the kidneys and will cause severe kidney malfunction and disease. This is a non-inflammatory disease that damages the glomeruli within the kidneys. When the glomeruli are damaged, protein and red blood cells are passed into the urine. When the protein and red blood cells are lost through the urine then edema, or the accumulation of fluid within the body, occurs. 

There is a genetic test that can be performed to determine if your dog is affected by hereditary nephritis. Responsible breeders will perform genetic testing on their breeding dogs prior to ever producing puppies to ensure that they are producing healthy puppies that are not affected by the condition.

Hereditary nephritis is X-linked and it is transmitted by mothers to sons through the X chromosome. Mothers can pass this condition to daughters but since females have two X chromosomes to males one X chromosome, the disease is less serious in females. Males that are affected generally will die by 15 months of age. 

Symptoms of hereditary nephritis, also known as Samoyed hereditary glomerulopathy, will occur very early in male puppies that are affected. Female puppies that are affected may have very mild symptoms or no symptoms until they are much older. If you suspect your dog is suffering from this kidney disease, you should schedule an appointment with your veterinarian for a proper diagnosis. 

• Vomiting 
• Poor appetite
• Weight loss
• Excessive thirst
• Excessive urination
• Lethargy
• Muscle weakness
• Edema in the paws and/or abdomen
• Protein in the urine
• Blood in the urine
• Chronic renal failure
• Anemia from renal failure
• Decreased kidney function
• Death

Hereditary nephritis (Samoyed) is a disease that is inherited from a carrier female. Males are more likely to be affected by it because they only have one X chromosome. Male puppies will begin showing symptoms of the kidney condition at an early age and will generally die from kidney failure by 15 months of age.

Females have two X chromosomes. Females can be affected but are less likely and the symptoms are slower to appear and tend to be milder. The mother will pass the hereditary nephritis gene onto her offspring.

There is a genetic test available to determine if your dog is affected by hereditary nephritis. Responsible breeders will have this genetic test performed prior to breeding a dog to ensure that they are not passing the gene onto future litters.

Your veterinarian will begin by taking down your dog’s medical history and a list of the symptoms that have already presented. A physical examination will be conducted and general diagnostic tests such as a biochemistry panel and complete blood count will be completed. These tests will show if there is any rise or fall in your dog’s red blood cell or white blood cell counts. They will also tell your veterinarian if your dog is anemic and assess organ functions. Your dog’s blood pressure will also be monitored while your veterinarian is determining the diagnosis. 

A urinalysis will determine if there is blood or protein present in your dog’s urine. A urine protein and creatinine ratio will also be performed to establish the severity of the protein being lost in the urine. This test requires that your dog’s urine be collected over a 24 hour period. 

There is a genetic test that is available. It examines the COL4A5 gene and reliably determines if your dog is a genetic carrier of hereditary nephritis or is affected with it. Male offspring born to a carrier female will have a 50% chance of developing the hereditary glomerulopathy. Responsible breeders will be looking for females who are not carriers or affected. These females have no increased risk of producing affected offspring.

Samoyed hereditary glomerulopathy, or hereditary nephritis, has no cure; this is a progressive condition that will eventually lead to death, especially in male dogs. Your veterinarian can provide a treatment plan that may slow the progression of the condition. A specialized diet that is low in salt, phosphorous and protein will be recommended for your dog. An Omega 3 supplement may also be added to your dog’s diet. 

ACE inhibitors, diuretics and immunosuppressant medication may be prescribed to control blood pressure and reduce edema. Your veterinarian may also recommend hemodialysis which is generally done by a veterinary specialist.

Speak with your veterinarian about treatment options to try to slow the progression of the condition. There is no cure and for males and for some females this condition is fatal. Carrier females will generally show mild symptoms or sometimes will exhibit no symptoms. 

Be sure to follow up with your veterinarian during your dog’s treatment plan so your veterinarian can properly assess your dog’s condition and their quality of life. Medications may need to be modified during your dog’s follow up visits.