The diagnostic tools and equipment in our lab allow us to gain insight into your cat or dog's health. Here, our veterinary specialists in Springfield talk about urinalysis for dogs and cats, what to know about the process and what it shows us about your pet's health.
What is urinalysis for dogs and cats?
Urinalysis is a veterinary diagnostic test where the urine is collected and examined to gain insight into the health of your pet and developing conditions. It can be used as part of regular preventive care and for diagnosing the cause of specific symptoms.
Why does your dog or cat need a urinalysis?
Your vet will use urinalysis to detect the overall health of the kidneys and urinary system. This method of diagnostic testing can also be used to diagnose conditions affecting other vital organs like the liver.
How is urine collected for urinalysis?
There are three ways that urine samples are typically collected:
Cystocentesis: This process uses a sterile needle and syringe to puncture the abdominal wall and collect the urine directly from the bladder. This method allows the urine to be collected without possible contamination from debris within the lower urinary passage. Cystocentesis is most commonly used when detecting bacterial infections and other issues with the kidneys and bladder. Unfortunately, this method can only be used when your dog has a full bladder and is cooperative.
Catheterization: This method of urine collection uses a catheter passed through the urethra and up into the bladder to extract urine. This option may be easier than cystocentesis as it is less invasive and easier to use. The downside is the possible irritation that may occur in the urethra and the chance of bacteria moving from the urethra and into the bladder during the process.
Mid-stream free flow: Collecting your dog or cat's urine as they relieve themselves is the easiest collection method. It is called mid-stream free flow because it is recommended that the urine is collected halfway through their voiding. This also allows you to collect urine naturally, before visiting your vet. Unfortunately, with this method, there may be a risk of sample contamination.
What happens during urinalysis?
Four main parts make up a urinalysis. They are:
- The assessment of the urine for cloudiness.
- Measuring the concentration of the urine.
- Gauging the acidity or PH of the urine.
- Microscopic examination of the cells and solid material present in the urine.
A standard urinalysis is performed by your vet looking at the urine sample as a whole. However, if your vet decides to complete a microscopic examination of the cells and solid material, they will need the urine sample to be concentrated or sedimented. To create a concentrated urine sample, your vet will place the sample of your pet's urine in a tube and run it through the centrifuge at very high speeds. This will cause the heavier materials to move to the bottom of the sample for analysis using a microscope.
How is urinalysis performed?
A chemical analysis is completed using a dipstick. A dipstick is a small strip of plastic that holds a series of individual test pads. The pads used in the dipstick are designed to change color depending on the concentration of different elements in the urine. The dipstick is dipped into the urine, and after a short waiting period, the color of the test pads is compared to a chart that translates the intensity of the color to an actual measurement.
What will be shown with urinalysis?
- Protein: The presence of protein in urine is called proteinuria. While trace amounts of proteinuria found in concentrated urine may not cause your vet to worry. Dilute urine of dogs and cats should not contain proteinurias as it is considered dangerous since it may indicate kidney disease. The significance of proteinuria is often determined by doing a second test called the protein creatinine ratio test.
- Glucose: Your vet should not find any glucose in your pet's urine. The presence of large amounts of glucose usually indicates your pet has diabetes. Small amounts of glucose in the urine may also be found in pets with kidney disease.
- Ketones: When your pet's body begins to break down stored fats as an energy source, it can result in the presence of ketones. This occurs most frequently in diabetes, but can also be found in healthy animals during prolonged fasting or starvation.
- Blood: If blood is found in the sample, it means that your dog or cat is experiencing bleeding somewhere within their urinary system. Sometimes this is due to how the sample was collected. For example, small amounts of blood are often found in samples collected by cystocentesis or catheterization. Blood in the urine is associated with diseases such as bacterial infection, bladder stones, trauma, or cancer. So if the blood in the urine does not appear due to the sampling method, further investigation is recommended.
- Hemoglobin: If your pet has hemolytic anemia, it can result in blood in the urine. Hemolytic anemia is when red blood cells are destroyed and a protein called hemoglobin is released. Hemoglobin passes into the urine and causes the blood test pad to show positive, even though there is no actual bleeding in the urinary system.
- Myoglobin: There is also the chance that blood may be present if your pet is experiencing trauma such as a torn muscle or ligament. This is because damaged muscle fibers release a protein called myoglobin, which is very similar to hemoglobin. Myoglobin will also cause the blood test pad to show positive, even though there is no actual bleeding in the urinary system. A specific test for myoglobin can be done if muscle injury is suspected.
- Urobilinogen: The presence of urobilinogen in urine indicates that the bile duct is open, and that bile can flow from the gallbladder into the intestine.
- Bilirubin: Bilirubin is a substance produced in the liver and normally excreted in the bile. Bilirubin is not found in the urine of healthy cats but may be found in small quantities in the urine of healthy dogs. Abnormal amounts of bilirubin in the urine are associated with liver disease or red blood cell destruction (called hemolysis), and should always be investigated.
Examining Your Pet's Urine Sediment
The chemical analysis using a dipstick can be very useful for identifying different aspects of your pet's health but there are some things it may miss. To cover these other areas, your vet may also perform a microscopic examination of the urine sediment. To examine the urine sediment, your vet will use a centrifuge in our veterinary diagnostic laboratory in Springfield to separate the different parts of the urine sample.
What is considered abnormal in urine sediment?
White Blood Cells: White blood cells present in the urine sediment can indicate an issue with the kidneys or bladder.
Red Blood Cells: If red blood cells are found then your pet may be experiencing trauma or irritation to the bladder or kidneys. Some of the conditions that red blood cells may be a sign of include:
- Bladder or kidney infections
- Bladder or kidney stones
- Interstitial cystitis (inflammation within the lining of the bladder)
- Cancer within the urinary tract system
Bacteria: Infections of the urinary system can be diagnosed with the discovery of bacteria in the urine sediment. In cases where bacteria are not present yet there are clinical signs of a urinary tract infection then your vet may request a urine culture be performed.
Casts: If a pet is experiencing damage to one of their kidneys then their body may 'shed' the lining within the tiny tubes that make up the tissue within the kidneys. Your vet will examine these casts if they are found in the urine sediment.
Crystals: While the pH of your pet's urine will likely stay within the normal range most of the time, there may the situations that result in the pH going into abnormal ranges allowing for the development of crystals. At times these crystals can be resolved naturally without causing further issues. If your vet notices an abnormally large number of crystals they may recommend a radiograph (X-ray) or ultrasound of your pet’s abdomen to look for bladder or kidney stones.
Other Cells: Pets with tumors may have abnormal cells present in the urine sediment. If your pet is experiencing irritated bladder walls they may shed cells into the urine which are called transitional epithelial cells.
Our Veterinary Diagnostic Laboratory in Springfield
Urinalysis performed in our veterinary diagnostic laboratory in Springfield, is a crucial part of determining the cause of particular symptoms and monitoring your cat or dog's ongoing health and bodily function.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.