Glomerulonephritis in Cats

Overview:

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

Glomerulonephritis occurs 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) & scarring. This impairs the filtering ability, causing blood & protein to be lost in the urine.

Glomerulonephritis often runs in conjunction with infections or other diseases, such as;

• Feline Leukemia Virus (FeLV

• Feline Immunodeficiency Virus (FIV)

• Feline Infectious Peritonitis (FIP)

• Heartworm infection

• Chronic bacterial infections

• Lupus

• Pancreatitis

• Neoplasia

Many cases of Glomerulonephritis are idiopathic (unknown causes)

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

What are the symptoms of glomerulonephritis in cats?

There are often no signs of the disease, most cases begin long before symptoms appear. There are two clinical forms of glomerulonephritis, the first is the nephrotic syndrome & these cats may develop;

• Subcutaneous build up (edema) of fluid

• Ascites (peritoneal cavity fluid)

The second form is renal failure & symptoms may include;

• Hematuria (blood in urine)

• Polydipsia (increased thirst)

• Polyuria (increased urination)

• Vomiting

• Anorexia

• Polyarthritis (inflammation in many joints)

• Weight loss

• Lethargy

Both forms have small, firm kidneys. The nephrotic syndrome possibly represents the early stage of glomerulonephritis & the renal failure the latter. [2]

How is glomerulonephritis diagnosed?

Your veterinarian will perform a complete physical examination of your cat & obtain a medical history from you. He will wish to perform some blood tests including;

• Complete blood count/biochemical profile/urinalysis to identify hypoalbuminemia (low blood protein), anemia, proteinuria (large amounts of protein in urine), hypercholesterolemia (high blood cholesterol).

• Specific tests for FeLV, FIP, FIV.

• As cats may also have hypertension (high blood pressure), your veterinarian may check blood pressure.  As is used on humans, in cats 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 & a Doppler or oscillometric device is used instead. 

• Kidney biopsy is the only method to give a definitive diagnosis of glomerulonephritis.

How is glomerulonephritis treated?

Treatment involves finding & treating the underlying cause if possible.

• 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 & 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)

Please note:

The medical articles on this site have not been written by a veterinarian & should not be considered a replacement for a veterinarian visit. The articles are provided for informative purposes only & should not be used for  the diagnosis or treatment of any medical condition. 

Always seek immediate veterinary advice for any problems (health or behavioral) in your pets. 

While great care has been made in the creation of these articles, we cannot guarantee the accuracy or omissions on these pages. If in any doubt whatsoever, seek professional medical advice.