Samoyed Hereditary Glomerulopathy in Dogs

SHG affects the Samoyed breed of dog. Samoyed hereditary glomerulopathy has similarities to hereditary nephritis (HN) in people; it is inherited in X linked fashion. Nephritis means inflammation of the nephron. Nephrons have two main parts; the glomerulus and the tubule. SHG is also known as X-linked hereditary nephritis because the disease is carried on the X chromosome.

What happens in Samoyed hereditary glomerulopathy is that the damaged filtration system (glomeruli and tubules) lets protein and red blood cells to leak into the urine.  The loss of protein, such as albumin in the urine causes the body to accumulate fluid in the body (edema). Normally albumin acts like a sponge in the bloodstream and is able to absorb extra fluid. SHG will also cause a buildup of toxins in the blood.

Samoyed hereditary glomerulopathy (SHG) in dogs is a non-inflammatory disease that causes the kidneys to malfunction. The disease damages the microscopic filtration system of the kidney, which is made of millions of capillaries. The damaged glomeruli are then unable to filter toxins from the blood.

Symptoms may appear as early as 3 to 6 months of age.  Symptoms may include:

• Excessive drinking and urination
• Vomiting
• Decreased appetite
• Lethargy
• Muscle weakness
• Anemia
• Hypertension (high blood pressure)
• Proteinuria (protein in the urine)
• Weight loss
• Hypoalbuminemia (albumin in the blood is low)
• Decrease kidney function
• Kidney (renal) failure

Samoyed hereditary glomerulopathy in dogs is an inherited disease.  It is passed in X chromosome-like fashion. DNA form structures called chromosomes, which carry genetic information from the mother to her offspring. 

Samoyed hereditary glomerulopathy progresses faster in males because they only have one X chromosome. Dogs have 39 pairs of chromosomes two of which are sex chromosomes.  Females have the same sex chromosome XX and males have XY chromosomes. Dogs diagnosed with Samoyed hereditary glomerulopathy should not be bred. If bred, the SHG mutated gene would be transmitted to the litter.

After a discussion about your pet’s medical background, the veterinarian will perform a physical evaluation. In addition to the assessment of the clinical signs, the veterinarian may suggest a complete blood count (CBC) and a serum chemistry panel.  The complete blood count can help determine if there are abnormalities in the red and white blood cell count, and verify the presence of bacterial infection and anemia.   A serum chemistry panel can help assess organ function.  

The chemistry panel can help determine albumin, bilirubin, BUN, total protein, glucose, sodium, potassium, and creatinine levels. The doctor may also recommend x-rays, urinalysis, and MRI scan. Your dog may have a urine albumin test or albumin/creatinine (ACR) ratio test.  The ACR requires urine collections samples over a 24-hour period.  There is also a genetic blood test that is available through specialized DNA laboratories.

There is no cure for Samoyed hereditary glomerulopathy in dogs.  The disease can’t be stopped but it can be slowed down with medications and a specialized diet regimen.   The veterinarian will recommend a diet that is low in protein, salt and phosphorous. A diet that is low in protein will help decrease the amount of protein filtered by the kidney.  Low sodium and phosphorous will help keep the blood pressure down. A homemade diet may be suggested.   The dietary supplement Omega 3 may be recommended to aid in decreasing the protein in the urine (proteinuria).

To further control high blood pressure, the patient may be prescribed an angiotensin-converting enzyme inhibitor (ACE inhibitors) and diuretics. Immunosuppressant medication such as cyclosporine may also be prescribed. 

Hemodialysis may also be recommended.  Hemodialysis is a treatment which uses a machine to filter and remove wastes and extra fluids from the blood.  The filtered blood is then returned to the body.  Depending on the condition of the patient he may need to stay overnight for his first treatment.  Additional hemodialysis treatment may be done as an outpatient.

There is no cure for Samoyed hereditary glomerulopathy but the effects of the disease can be slowed down.  The treatment plan provided by the veterinarian may increase the patient’s lifespan and improve his quality of life.

Follow up visits will be necessary to monitor your dog’s condition and to assess if there are any side effects to the medications.  Pet owners must be committed to follow the on-going treatment plan for SHG.