Our veterinarian tested a sample of urine from our dog Muffin to diagnose a kidney infection. Since then, I've been curious about how just a few drops of urine can reveal so much. Can you explain?
It does seem remarkable that so much information can come from such a simple procedure and such a small amount of urine. Testing a pet's urine, whether from a dog or cat, is a very valuable diagnostic aid in uncovering problems in the liver, pancreas, and bladder as well as the kidneys.
Part of our urine analysis is to determine its specific gravity. This can tell us how well the kidney tubules are concentrating the urine which is important information for determining kidney function.
A simple reagent strip can be dipped into the urine to show several things. Glucose in the urine points to diabetes and bilurubin can be associated with underlying liver problems. The protein level can help us find kidney damage (nephritis), and blood in the urine can indicate inflammation that might be caused by a bladder infection or kidney disease.
We can spin the urine in a centrifuge, then check the sediment at the bottom of the test tube under a microscope. The different cells and crystals we find can provide a wealth of information. If we suspect a tumor in the bladder or kidney, we stain the cells so we can find tumor cells. We can see bacteria and white blood cells which can indicate infection. Certain crystals tell us if there are bladder or kidney stones.
All this information is even more valuable when it is combined with a complete blood profile and radiographs and possibly a urine culture. As you see, a little urine and the tests we perform on the sample provide a wealth of information.