Choosing the Right Vet for Your Pet

Understanding Your Cat's Kidney Function Values

As your feline friend enters her golden years, your veterinarian will recommend laboratory screenings to assess her health status. While your veterinarian will be evaluating all of your cat's laboratory results, he or she is especially interested in the values that indicate renal function. Understanding these values and tracking them through periodic testing can be instrumental in extending your cat's quality of life.

The Importance of Testing

Chronic kidney disease is one of the most common health conditions to afflict senior cats. It is an incurable disease that progresses to kidney failure and death. With early detection, treatment can retard its progression and provide your cat with a longer and better quality of life. To accomplish early detection, a blood chemistry panel and urinalysis should be performed at least annually. The three primary values that tell the tale of how well your cat's kidneys are functioning include the following:

  • Creatinine
  • BUN
  • Urine Specific Gravity

Creatinine Results

One indicator of kidney function is the creatinine level in your cat's blood. Creatinine is the waste product that results when creatine is metabolized. Creatinine is filtered from the blood by the kidneys and expelled from the body through urination. An elevated creatinine level indicates that the kidneys are not performing their task efficiently. The general normal reference range for creatinine in cats is 0.6 to 2.4 mg/dL. There are four stages of chronic kidney disease, which are categorized as follows:

  • Stage one applies when the creatinine level is less than 1.6.
  • Stage two applies when the creatinine level ranges between 1.6 and 2.0.
  • Stage three applies when the creatinine level ranges between 2.9 and 5.0.
  • Stage four applies when the creatinine level exceeds 5.0

As you can see, the values of the first two stages actually fall within the normal general reference range. Certain factors, including medications, diet and dehydration, can cause mild elevations in a pet's creatinine level. Therefore, your veterinarian will also evaluate another value in your cat's blood chemistry panel results.

BUN Results

BUN stands for blood urea nitrogen, another key value in assessing renal health. Urea is the waste product that is produced in the liver from ammonia, another waste product that results through the metabolism of protein. As with creatinine, when your cat's kidneys are no longer able to remove urea from the blood, the toxin accumulates, showing as an elevated BUN value. The normal reference range for BUN in cats is 14 to 36 mg/dL. When creatinine and BUN levels are both elevated, this combination is known as azotemic, and it is a strong indicator of failing kidney function. A third value, one that is revealed in your cat's urinalysis results, solidifies the diagnosis.

Urine Specific Gravity Results

Urine specific gravity is the value that indicates how effectively your cat's kidneys are concentrating urine. The normal reference range for a cat's urine specific gravity is 1.015 to 1.060. As healthy kidneys carry out the task of filtering wastes from the blood to be eliminated through urination, that urine is concentrated and should fall within this range. As the kidneys fail to keep up with their filtration duties, wastes do not make it into the urine. The result is diluted urine, which presents as a low urine specific gravity value.

Early signs of chronic kidney disease include increases in water intake and urination. These symptoms can also be signs of other health conditions that often strike senior cats, including diabetes and hyperthyroidism. By the time most cases of chronic kidney disease are diagnosed, the kidneys have permanently degenerated by approximately 75 percent. Your can help to extend your cat's life by keeping a close watch over your cat's drinking and urination habits and following your veterinarian's laboratory testing recommendations.

For more information, contact Babylon Animal Hospital or a similar location.