Glomerulonephritis

Glomerulonephritis describes inflammation of the glomeruli — the tiny filtering units inside the kidneys that clean the blood and produce urine. When these filters become inflamed, they may leak protein into the urine or allow waste products to build up in the bloodstream, and in some cases both processes occur together. The condition can develop suddenly or progress quietly over months, and the underlying cause is not always apparent at the time it is recognised. Owners often arrive at this page after routine bloodwork or urine testing has shown changes such as protein in the urine, elevated kidney values, or low albumin in the blood. Some dogs or cats show visible signs such as reduced appetite, weight loss, or swelling in the legs or abdomen, while others appear well and the findings emerge during screening for another concern. The pattern of signs depends on how much the filtering function has been affected and whether the condition has triggered secondary changes elsewhere in the body. This page explores what glomerulonephritis may look like in daily life, what processes underneath can lead to inflammation of the kidney filters, how the condition is investigated through blood tests, urine analysis, and sometimes tissue sampling, and the range of approaches that exist to address the inflammation, support kidney function, and manage complications that may develop over time.