1 in 3 cats will develop kidney disease during their lifetime. The signs are subtle, and the disease can progress to kidney failure before it's recognized. Thankfully, there are screening tests available to monitor your cat's kidney health, so we can intervene and slow down the disease before your cat ever feels ill.
The kidneys play a key role in filtering the blood and removing waste products. As their function decreases, those waste products build up in the blood and cause illness. The kidneys are also important in balancing electrolytes. Kidney disease allows important salts and proteins to leak through and be lost in the urine.
How to diagnose kidney disease:
Cats 7 years old and older should have screening for kidney disease done every year, and twice per year after they're 10 years old. This gives us the best chance of catching kidney disease in its early stages, where simple diet change can have a huge impact. If you notice any of the signs of kidney disease in your cat, your veterinarian can run a few simple tests to assess kidney function. We start with a complete physical exam, including palpating the kidneys. Cats with chronic kidney disease often have small firm kidneys. We then run blood and urine tests and check blood pressure.
The earliest blood marker of kidney disease is SDMA. It can detect as little as 1/4 kidney function loss, well before there are any outside signs of illness.
Creatinine and BUN increase when 3/4 of kidney function is lost. The cats usually feel ill as these increase.
Isosthenuria, where the concentration of the urine is the same as the blood plasma, occurs once approximately 2/3 of kidney function is lost.
Proteinuria, where the kidneys leak protein, requires special additional treatment.
We also evaluate for red and white blood cells, bacteria, abnormal urinary tract cells or casts, and crystals. These can indicate infection or ongoing kidney injury.
Cats with chronic kidney disease often develop hypertension. This then causes more kidney injury as the high blood pressure damages the remaining functioning kidney. We can interrupt this vicious cycle with appropriate medication.
Treating Kidney Disease:
While there's no cure, cats with chronic kidney disease (CKD) can live for years with good quality of life if their disease is managed. Frequent monitoring is the key to success so treatments can be adjusted.