Glomerulonephritis in Dogs

The glomeruli are an essential part of how the kidneys clean the blood and separate out waste products into the urine. A single glomerulus is a tiny ball of coiled blood vessels in the kidney. The high surface area of the coils allows for waste products to diffuse across the blood vessel wall and into the urine-collecting portion of the kidney. Glomerulonephritis occurs when a chunk of immune cell products, such as antibodies stuck to a bacterial plaque, gets stuck in the tangle of blood vessels. It is unusual for these so-called immune complexes to grow large enough to obstruct the glomeruli, and so this condition usually occurs concurrently with serious illnesses like Lyme disease and inflammatory autoimmune diseases. If you notice blood your dog’s urine, see a veterinarian right away, as this is the most common sign of possible glomerulonephritis.

• Blood in urine (most common)
• Loss of appetite
• Increased thirst
• Excessive urination
• Vomiting
• Lethargy
• Loss of weight
• Renal failure (will develop in approximately 70% of patients)

• Chronic gum disease
• Cancer
• Inflammation of the prostate
• Heartworm infection
• Lyme disease
• Endocarditis
• Autoimmune disease (E.g., lupus)
• Inflamed skin
• Ehrlichia infection (tick-borne)

Owners who notice blood in their dog’s urine, or any weakness, lethargy or weight loss should bring their dog to a veterinarian as soon as they can, especially in areas where ticks are common. The veterinarian will make a physical examination of your dog, checking for signs of edema (fluid buildup) and inflammation. A urine sample will also be collected for analysis, which will give the clearest picture of what is occurring. Glomerulonephritis is indicated by a specific set of characteristics, such as the presence of blood and elevated protein levels in the urine. Hyaline casts are another key symptom- these are microscopic protein structures that form in the shape of the kidney’s tubing and indicate damage.

The veterinarian will likely take a blood sample to see if your dog is anemic and measure levels of inflammatory factors that might signal an infection. An X-ray might be taken as well to rule out any masses on the kidney. Finally, a kidney biopsy may be performed, taking a small sample of tissue for analysis. This is an important test to distinguish glomerulonephritis with amyloidosis, another serious kidney disease.

If no underlying infection can be found, a course of steroidal anti-inflammatories can be given at low dosage. Moderate improvement and lack of fever after a few days of treatment may suggest an autoimmune or idiopathic case of glomerulonephritis. Up to 70% of cases occur with no identifiable cause.

The treatment will vary based on the underlying condition. Infections will usually be treated with antibiotics and supportive care such as IV fluids. Autoimmune diseases may require immunosuppressant drugs to control inflammation and stop the body from attacking itself.

The primary condition, being inflammation and obstruction of the glomeruli, can be treated with a very low dose of aspirin to curtail excessive clotting. This treatment may also include Omega-3 fatty acid supplements. A low-protein, low-phosphorus diet should be given to pets experiencing kidney troubles. Steroidal anti-inflammatories can be given where no infection is present, and gradually tapered off at the direction of a veterinarian. If there is any form of hypertension a low sodium diet should be followed strictly.

The recovery of your dog will depend on any underlying conditions causing the glomeruli to become obstructed and inflamed. Endocarditis, a bacterial infection of the heart, is a serious condition which does not always respond to antibiotics in time, and can permanently weaken and damage the heart if not treated promptly. High blood pressure as a result of kidney problems is serious in its own right, and blood-pressure regulating medication and diets will have to be followed at the direction of the veterinarian.

Idiopathic glomerulonephritis may re-occur once treatment is tapered off, and so follow-up visits including urinalysis and blood tests will be needed. Evidence indicates that supplementing your pet’s diet with omega-3 fatty acids can reduce inflammation and clotting, and a low-sodium diet with care to avoid excess protein can help blood pressure and general kidney function.