Issue Description Glomerulonephritis is a renal disease
characterized by inflammation of the glomeruli, or small blood vessels
in the kidneys. Other Names Glomerulonephritis, GN
Causes Glomerulonephritis occurs when large numbers of
immune complexes - these are antigen-antibody complexes - circulating
in the bloodstream become trapped in the glomeruli as they attempt to
pass into the urine. Deposition of immune complexes triggers an
inflammatory reaction that damages the glomeruli and results in
proteinuria. The antigens bound to the antibodies in the immune
complexes arise as a result of some chronic infectious, inflammatory
or cancerous disease process. Several diseases have the potential to
result in glomerulonephritis.
Some Causes Include:
Infectious hepatitis in dogs (canine adenovirus 1)
Lyme disease (borreliosis)
Ehrlichiosis (an infectious disease transmitted by ticks)
Rocky Mountain Spotted Fever (another disease transmitted by
Brucellosis (an infectious disease)
Dermatitis (infection of the skin)
Gingivitis (infection of the gums)
Endocarditis (infection of the heart valves)
Prostatitis (infection of the prostate)
Pyometra (infection of the uterus)
Chronic fungal infections
Leishmaniasis (a protozoal infection rarely encountered in the
United States and transmitted by sandflies)
Non-infectious inflammatory diseases that
have been associated with glomerulonephritis include:
Pancreatitis (inflammation of the pancreas)
Immune-mediated polyarthritis (inflammation of the joints)
Despite the long list of infectious, inflammatory and neoplastic
disease processes that can result in glomerulonephritis, in as many as
75 to 80 percent of dogs and cats with glomerulonephritis, the
underlying cause cannot be identified and the disorder is referred to
Symptoms The presenting complaint in dogs and cats with
glomerulonephritis is variable and depends on the severity and
duration of urine protein loss as well as the presence or absence of
kidney failure and complications.
Clinical signs associated
with mild to moderate proteinuria may be non-specific, such as weight
loss and lethargy. With severe protein loss, fluid accumulation in the
abdomen and in other areas of the body may occur, although this is
uncommon. If the glomerular disease is extensive, kidney failure and
resultant vomiting, inappetance increased drinking and urination, bad
breath, and nausea may occur. Occasionally, signs associated with an
underlying infectious, inflammatory, or cancerous disease may be the
reason the owner seeks veterinary care.
Diagnosis Persistent, severe elevations in protein in the
urine with an otherwise normal urinalysis are the hallmark of
Other laboratory tests such as a urine
protein, creatinine ratio and blood work can be used to help confirm
the diagnosis. The only way to definitively diagnosis
glomerulonephritis is with a biopsy of the kidney.
with protein in their urine should be thoroughly evaluated for
underlying infectious, inflammatory, or cancerous conditions. Testing
may include blood tests for regional infectious diseases, urinalysis,
x-rays of the chest, abdominal x-rays or ultrasound.
The most important treatment for
glomerulonephritis is the identification and treatment of any
underlying disease. The dog or cat should be subsequently evaluated
for resolving protein in the urine.
It is believed that uncontrolled proteinuria leads to progressive
kidney damage. Angiotensin-converting enzyme inhibitors (ACEI) are a
type of medication often used to help reduce protein levels in the
urine. If high blood pressure is present, additional medications may
be needed to help lower it.
Low doses of aspirin are often given to prevent blood clots and
further glomerular damage.
Immunosuppressive medications such as prednisone may be used in
Dietary protein restriction may be useful in the management of
Increased blood pressure with resultant
retinal detachment or hemorrhage may occur. Acute blindness due to
retinal detachment may be the first complaint of dogs with
Increased coagulability of the blood with resultant blood clots
are another complication associated with glomerulonephritis. The lungs
are the most common location for a blood clot to lodge, and may result
in severe respiratory illness that is difficult to treat.
Prognosis The prognosis for dogs and cats with immune
complex glomerulonephritis is fair to guarded unless the causative
underlying disease can be identified and eliminated. A reduction in
proteinuria with no increase in blood renal values indicates
improvement or response to therapy.