Polycystic Kidney Disease in Cats

Polycystic kidney disease is an inherited condition in which fluid-filled pockets—cysts—develop within the kidney tissue over time. These cysts gradually enlarge and multiply, slowly replacing the normal working tissue of the kidney. The condition is present from birth, but signs typically emerge in middle age as the cysts occupy more space and the kidneys begin to lose function. Many cats show no outward signs for years. When changes do appear, they often reflect the kidney's declining ability to filter waste and regulate fluid balance—weight loss, increased thirst, changes in appetite, or a generally quieter demeanour. Some owners notice the condition through routine imaging or blood work before any signs are visible at home. This page explores the patterns an owner may observe, what is happening inside the kidney as cysts develop, how the condition is identified and monitored, and the range of approaches used to support kidney function and quality of life over time.