Renal Dysplasia in Dogs (Familial Renal Disease)

Overview of Canine Renal Dysplasia

Renal dysplasia, also known as familial renal disease or progressive juvenile nephropathy, is a disease in which development of the kidney tissue is abnormal. In dogs, the clinical signs of the disorder typically occur before the age of two years. Ultimately, renal dysplasia can result in Chronic renal (kidney) failure and death.

Kidney failure is the malfunction of the kidneys to filter waste products produced by the body. Waste products are normally carried by blood to the kidneys to be filtered and excreted in the form of urine. When the kidneys fail, they are no longer able to remove these waste products causing toxins to build up in the blood producing clinical signs of kidney disease. Kidney failure affects almost every body system causing many changes throughout the body and usually results in the following:

• Abnormal filtration of blood and retention of waste materials
• Failure of hormone production (including substances that stimulates the production of red blood cells [erythropoeitin])
• Inability to convert vitamin D to form calcitriol which is important in normal bone development
• Disturbance of fluid, electrolyte and acid-base balance

The disease is most commonly inherited. It is more common in dogs that cats. It can occur in any breed, age or sex. Most animals begin to show symptoms of disease before the age of 2 years. Breeds predisposed to renal dysplasia include the cocker spaniel, Lhasa apso, golden retriever, shih tzu, Dutch kookier, Finish harrier and soft-coated wheaten terrier.

What to Watch For

Signs of renal dysplasia in dogs may include:

• Anorexia or reduced appetite
• Depression
• Lethargy
• Increased thirst and urination (polydipsia and polyuria[PU/PD])
• Weight loss
• Bone pain
• Occasional vomiting
• Diarrhea
• Stunted growth
• Hematuria (bloody urine)
• Abnormal bone structure (such as enlarged mandible/maxillae or pathologic fractures

Diagnosis of Renal Dysplasia in Dogs

Physical examination findings and routine laboratory data are recommended for diagnoses. The results will vary depending on the severity of the disease.

• Complete blood count may show signs of anemia.
• Serum biochemical profile may indicate abnormally elevated kidney values including the blood urea nitrogen (BUN) and creatinine. Additional abnormalities may include high phosphorus, low potassium, high or low calcium, high cholesterol, and low albumin levels.
• Blood pressure may be abnormally elevated (hypertension).
• Urinalysis may demonstrate poorly concentrated urine and possibly abnormal blood, protein or glucose.
• Radiographs. X-rays may show abnormally small kidneys or soft-tissue mineralization.
• Ultrasound. This is a sensitive, non-invasive technique for diagnosing kidney disease. Ultrasound may show small irregularly shaped kidneys.
• Biopsy. Histopathic evaluation of the kidney tissue confirms the diagnosis.

Treatment of Renal Dysplasia in Dogs

There is no specific treatment for renal dysplasia in dogs. Treatment is the same as that for chronic kidney failure of any cause, for example:

• Rehydration with intravenous or subcutaneous fluids
• Restricted protein and phosphorus diets
• Phosphorus binders
• Calcitriol (Vitamin D)
• Erythropoietin
• Control of vomiting with antiemetic drugs
• Control of hypertension
• Pain control for bone pain
• Frequent monitoring of blood levels to determine results of therapy

Home Care and Prevention

There is no specific home care for dogs with renal dysplasia that have no symptoms. Dogs with renal dysplasia that have developed chronic kidney failure undergo home care typical for that condition including:

• Prescription diet
• Possible subcutaneous fluid therapy
• Medication

There is no way to slow the progression or prevent the onset of chronic renal failure once renal dysplasia has been diagnosed. Prevention requires responsible breeding.