Using Canine Urinalysis for Detecting Kidney Disease

When a dog is suspected of having kidney disease, canine urinalysis is typically the first step taken in the diagnostic process. The veterinarian collects a urine sample from the dog and conducts several dip tests and macroscopic and microscopic examinations on the urine to determine if kidney disease is present. Once the urine sample has been examined, blood work is done to not only confirm the diagnosis, but to determine the extent to which the disease has progressed.

Macroscopic (Visual) Examination of Canine Urine

The veterinarian will examine the urine visually, checking for color and clarity. Normal urine color should be pale to dark yellow and clear. Cloudiness of the urine is indicative of protein in the urine, an indicator for kidney disease.

Dip Tests for Determining Kidney Disease

Various paper test strips are utilized to run the dip tests on urine. The results of these tests can help determine the level of kidney health.

Specific gravity indicates the level at which the kidneys can concentrate or dilute the urine. This test is typically run when the dog has not had food or water for 12 hours.
Protein in the urine is also detected through a dip test. While some protein is expected, protein levels more than 150mg in a 24 hour period are excessive and considered nephrotic (kidney) syndrome.

Microscopic Urinalysis for Kidney Disease

Microscopic urinalysis is conducted on urine that has been run through a centrifuge to separate the various components of the urine. Examination of the sediment determines if there are crystals, bacteria, cells or other large objects being excreted in the urine. These can indicate problems with kidney function.

Red blood cells in the urine can be an indication of any number of problems, including kidney disease. Normally there shouldn't be any red blood cells in the urine, but it can happen even in healthy dogs.

Epithelial cells are usually sloughed off into the urine in small quantities. This level is significantly increased in dogs with kidney disease.

Blood Tests for Determining Kidney Function

The veterinarian may want to run blood tests in conjunction with the urinalysis. The blood work will determine how effectively the kidneys are cleaning the blood, ultimately giving a specific picture of the dog's kidney health.

BUN (Blood Urea Nitrogen) is an indicator as to how effectively the kidneys are excreting urea, a waste product, from the blood. Elevated BUN readings alone do not indicate kidney disease.

Creatinine levels are a good standalone test for kidney problems as elevated creatinine readings are an indication of kidney problems and kidney problems only. Elevated creatinine increases toxicity in the blood and will present with neurological symptoms.

There are several causes of kidney disease in dogs. Age, tick borne diseases, dehydration, kidney trauma and other factors can all contribute to overall renal function. By identifying kidney disease early, appropriate action can be taken to slow the progression of the disease. Proper nutrition and hydration are key to caring for a dog with impaired kidney function. It is through urinalysis that the disease can be diagnosed and appropriate care can be given.