Glomerulonephritis in Cats

At a glance

About: Glomerulonephritis is an immune-mediated disease that involves inflammation of the glomeruli, which are the filtering units of the kidneys.

Causes: There are a number of causes of glomerulonephritis including bacterial or viral infections, lupus, pancreatitis, and tumours.

Symptoms: Fluid build up in the abdomen, increased thirst, and urination, blood in the urine, lethargy, bad breath and vomiting.

Treatment: Address the underlying cause as well as supportive care such as diuretics to remove excess fluid, corticosteroids, blood pressure medication and low sodium, high protein diet.

What is glomerulonephritis?

Glomerulonephritis in cats

Glomerulonephritis is an immune-mediated disease that involves inflammation of the glomeruli, which are the filtering units of the kidneys that are responsible for filtering waste products and excess water from the blood.

Causes

Glomerulonephritis has immunologic and non-immunologic causes. Immunologic causes occur as a result of immune complexes (an immune complex is an antibody which is bound to an antigen) becoming trapped in the glomeruli leading to inflammation (swelling) and scarring. This impairs the filtering ability, causing blood and protein to be lost in the urine.

Many cases of Glomerulonephritis are idiopathic (unknown causes)

There is no breed predisposition, but young males are more commonly affected. [1]

Symptoms

There are often no signs of the disease, most cases begin long before symptoms appear. There are two clinical forms of glomerulonephritis, nephrotic syndrome and renal failure.

Nephrotic syndrome symptoms

  • Subcutaneous buildup (edema) of fluid
  • Ascites (peritoneal cavity fluid)

Renal failure symptoms

Both types result in small and firm kidneys. Nephrotic syndrome possibly represents the early stage of glomerulonephritis and the renal failure the latter. [2]

Diagnosis

Your veterinarian will perform a complete physical examination of your cat and obtain a medical history from you.

Diagnostic workup

  • Biochemical profile, complete blood count, and urinalysis to identify hypoalbuminemia ( a low blood protein), anemia, proteinuria (large amounts of protein in the urine), hypercholesterolemia (high blood cholesterol).
  • Specific tests for FeLV, FIP, FIV, and heartworm.
  • As cats may also have hypertension (high blood pressure), your veterinarian will check blood pressure. An inflatable cuff is placed on the cat’s front leg or tail. In humans, a stethoscope is also used, this isn’t possible in cats and a Doppler or oscillometric device is used instead.
  • A kidney biopsy is the only method to give a definitive diagnosis of glomerulonephritis.

Treatment

The goal of treatment is to find and address the underlying cause as well as manage complications of kidney failure such as uremia (build-up of toxins in the blood).

  • Diuretics to remove excess fluid.
  • Corticosteroids to reduce inflammation
  • Medication which helps reduce blood pressure, these are usually calcium channel blockers, beta-blockers, ACE inhibitors, and diuretics. The calcium channel blocker amlodipine is most often prescribed. Medications won’t cure high blood pressure but will assist in controlling it.
  • Low sodium, high protein diets may be of help.

References:

[1] The Feline Patient – Gary D, Norsworthy, Mitchell A. Crystal, Sharon K. Fooshee, Larry P. Tilley (page 236)

[2] The Feline Patient – Gary D, Norsworthy, Mitchell A. Crystal, Sharon K. Fooshee, Larry P. Tilley (page 236)



Julia Wilson is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. She enjoys photography, gardening and running in her spare time. Full author bio Contact Julia