Urine tests indicate overall health

We often inform you about tests your pet is likely to have performed as routine screenings, as preoperative tests or to diagnose illness.

Now, we’re going to look at urine tests.

The most basic is urinalysis, performed in two parts. The chemical part of the urinalysis is performed with a dipstick, a strip of plastic with paper squares with chemicals to detect normal and abnormal components in the urine. The components are indicated by the color change on the square. The color on the strip is compared to colors on a chart to determine the test result.

The first test square is pH, which tells how much acid is present or absent. Most dogs’ and cats’ urine should have a pH of 7.0 (neutral) or less (meaning more acid). A high pH may indicate a recent high-carbohydrate meal, an abnormality in metabolism or a urinary tract infection caused by bacteria creating base, the opposite of acid.

Color change in the next test square indicates blood in the urine, which is always abnormal. If there is enough blood that you can see red, you should call your pet’s doctor right away. It may result from infection, physical trauma such as a blow, bleeding growths or bladder stones. Sometimes tiny blood vessels can be damaged in the process of obtaining the urine sample. If the amount of blood is very small, the clinician may take that into account.

A test square to indicate protein in the urine is very important, because several kinds of urinary tract diseases “spill” protein into the urine. Bladder infections may damage blood vessels, releasing protein from the blood. Infections and other diseases may damage the kidneys, causing loss of protein. Anything more than the tiniest amount of protein in the urine is abnormal. Some inherited kidney diseases in certain breeds of dogs and cats will first be detected in the very young animal by testing the urine for protein.

Never should there be glucose (sugar) in the urine of a normal patient. A diabetic patient may be allowed to have glucose in the urine temporarily, but even then not for long periods of time. Glucose in the urine may mean kidney damage is allowing glucose to be “spilled” into the urine. It can also mean blood levels of glucose are excessively high, as occurs in diabetes mellitus. Extreme excitement or short-term stress can also elevate blood glucose, especially in cats.

Related to diabetes mellitus and glucose metabolism is the ketone test square. Ketones in the urine are always abnormal, and represent an abnormality in glucose metabolism. Ketonuria is most commonly seen in poorly regulated diabetics.

Urobilinogen and bilirubin are tests to help differentiate liver disease from destruction of red blood cells in the bloodstream.

Next comes the microscopic portion of the urinalysis. This part is harder and more time-consuming, but both parts must be performed to have a complete picture of the patient’s urinary tract and metabolic health.

The microscopic portion of the urinalysis can be stained or unstained. We’re not talking about spilling the urine on the veterinarian’s clothing; we’re talking about applying stain to a thin layer of wet urine on a microscope slide. Some like it plain, some like it stained.


— Dr. Jim Randolph is a veterinarian at Animal General Hospital in Long Beach, Miss.