Glomerular Disease in Dogs

Glomerular disease, also known as Glomerulonephritis, is a specific type of renal or kidney disease characterized by inflammation of the glomeruli. Glomeruli are tiny structures in the kidneys that act as filters for the blood.

Each kidney contains millions of glomeruli; microscopic filtration units that interface with the blood vessels that supply the kidneys. Think of glomeruli as a tiny sieve or colander because the size of glomerular pores dictate which substances within the blood are allowed to enter into the fluid that ultimately becomes urine. Normal glomeruli do not allow larger protein molecules such as albumin to pass into the urine.

When the vessels become inflamed and subsequent impairment is referred to as glomerulonephritis. The most common cause of glomerulonephritis is the deposition and entrapment of antigen-antibody complexes (such as a toxin or enzyme) within the glomeruli.

This condition affects purebreds and mixed-breeds alike, and can be an inherited disorder in Shar Peis, Soft Coated Wheaten Terriers, Bull Terriers, Dalmatians, Samoyeds, Bernese Mountain Dogs, Doberman Pinschers, Newfoundlands, and English Cocker Spaniels.

Causes of Glomerular Disease in Dogs

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

Signs and Symptoms of Glomerular Disease in Dogs

The most common sign of glomerulonephritis is blood in the urine.

Other signs may include:

• Lethargy
• Vomiting
• Loss of appetite and weight loss
• Increased thirst and urination

If you notice any of the above signs, bring your dog to the veterinarian immediately. Glomerulonephritis can lead to a nephrotic syndrome where their damaged kidneys leak protein from the blood into the urine.

Dogs with nephrotic syndrome will have:

• Swollen legs
• High blood pressure
• Abnormal blood clotting

Diagnosing Glomerular Disease in Dogs

If a dog demonstrates persistent proteinuria (repeatable on multiple tests over the course of a few weeks), a battery of tests is typically recommended to rule out non-glomerular causes of excess protein within the urine such as urinary tract infection, stones, or bleeding. This testing typically includes the following:

• Complete blood cell count (CBC)
• Blood chemistry profile
• Urinalysis
• Urine culture
• Abdominal ultrasound or x-rays

Other tests may be recommended for purposes of ruling out heartworm disease, infectious processes, cancer, and other diseases that can cause secondary glomerular damage. 

Treatment

As most cases of glomerulonephritis involve an immune reaction (interaction of antigen and antibodies), the most specific and effective therapy is the control and elimination of such an immune reaction. However, finding and treating the exact disease process or antigen that is causing such an immune reactions is not always possible. Moreover, once renal failure has developed, the prognosis is often poor. The overall treatment of this disease depends on the cause and severity of the disease at the time of diagnosis.