Glomerulonephritis in Cats

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  • 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 several 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 that 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 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

    • Baseline tests: 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).
    • Antigen or antibody tests: Blood tests to look for the presence of antigen or antibodies to FeLV, FIP, FIV and heartworm.
    • Blood pressure check: 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.
    • Biopsy: 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 that helps reduce blood pressure, including usually calcium channel blockers, beta-blockers, ACE inhibitors, and diuretics. Amlodipine is the most frequently prescribed calcium channel blocker. 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)

    Author

    • Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She 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. Full author bio