An enlarged kidney can be a mild situation or a sign of more serious problems. Inflammation in the kidneys is caused by cysts, tumours and other diseases. By far the most common cause is kidney disease. By definition, the inflammation of the kidney is most likely to lead to kidney disease whether that is the cause or not.
Cats need only one functioning kidney to live a healthy life. If only one kidney is swollen and the other kidney is functional, the cat should be fine. Cats with swollen kidneys, though, may be suffering from more serious complications, and may be heading toward serious problems. Any cat with a swollen kidney, extensive thirst or anorexia should receive blood testing to diagnose whether it has a serious problem.
Feline Kidney Disease
Feline kidney disease, or kidney failure, is the most likely cause for a swollen kidney. Kidney disease occurs when the cat's kidneys break down and stop working the way they should. Instead of filtering toxins out of the blood and passing them to the urinary tract, damaged kidneys retain water and cause some serious physical repercussions.
Inflammation damages kidneys, and they become enlarged as an effect of that damage. Kidneys that are damaged fail to filter the blood and allow toxins to build up in the body. The kidneys then retain water, leading to further inflammation. Cats fail to gain nutrition from the food they eat, so they tend to lose weight. They also increase their water intake in an attempt to filter the toxins from their system. Increased thirst and urination are sure signs that the enlarged kidney is a product of kidney damage.
Kidney damage is generally caused by dried commercial food diets, so the main treatment for the damage is to alter the diet. Vets prescribe raw food diets or high-quality, high-protein canned food to aid kidney function and help cats to live healthy lives.
Kidney disease is an incurable problem. Although you can manage a cat's diet and lifestyle, kidney damage will never be undone. A cat who has kidney disease, or a disorder like enlarged kidney that will lead to kidney damage, requires a schedule of lifelong management.