Regular urinalysis testing is vital for your pets as it can help identify various health conditions and diseases that your cat or dog may have. Our veterinarians at Mankato explain why it is essential to conduct these tests regularly.
Urinalysis for Pets
A urinalysis is a test that checks the physical and chemical features of urine to evaluate the health of your pet's kidneys and urinary system. It can also detect problems with other parts of the body. If your pet is eight years or older, it's best to have a urinalysis every year. Additionally, a urinalysis may also be recommended if your pet is drinking more water than usual, urinating more frequently, or has blood in their urine.
Collecting a Urine Sample
There are three main ways to collect urine from cats and dogs:
Cystocentesis: To get a clean urine sample for evaluating the bladder and kidneys and detecting bacterial infection, a sterile needle and syringe are used to collect urine directly from the bladder. This procedure is called cystocentesis and ensures that the sample is not contaminated by debris from the lower urinary tract. It is slightly more invasive than other methods and only works if the pet's bladder is full.
Catheterization: Catheterization is a method of collecting urine from a dog's bladder without causing too much discomfort or harm. This method is especially useful when it's difficult to get a urine sample voluntarily, especially for male dogs. A small, sterile tube called a catheter is inserted into the bladder through the urethra.
Mid-stream Free Flow: When a pet pees on their own, their urine is collected in a clean container. This kind of sample is often called a "free flow" or "free catch" sample. It's a great method because it doesn't harm the pet, and the owner can easily collect the sample at home.
Understanding the Results of a Urinalysis
There are four main parts to a urinalysis:
- Assess appearance: color and turbidity (cloudiness).
- Measure the concentration (also known as the density) of the urine.
- Measure pH (acidity) and analyze the chemical composition of the urine.
- Examine the cells and solid material (urine sediment) present in the urine using a microscope.
When collecting urine samples, it's important to read them within 30 minutes of collection. This is because other factors like crystals, bacteria, and cells can change the composition of the urine over time. If you collect a urine sample at home, return it to your veterinary clinic as soon as possible. Timing of urine collection is usually not important unless we are testing for Cushing's disease or your pet's ability to concentrate urine. In those cases, it's best to collect the sample first thing in the morning.
Color & Turbidity
The color of a pet's urine can tell us a lot about their health. Pale yellow to light amber and clear urine is normal and healthy. However, dark yellow urine means they need more water or may be dehydrated. If their urine is not yellow, like orange, red, brown, or black, this could be a sign of a health issue.
If the urine looks cloudy, it means there are solid materials like cells, blood, crystals, mucus, or debris in it. The vet will examine the sediment to figure out what's going on and if it's a problem that needs to be treated.
When a healthy kidney produces urine, it can be more concentrated (dense) or watery (dilute). If there is too much water in the body, the urine will be more dilute, and if there isn't enough water, the urine will be more concentrated. If a dog or cat occasionally has dilute urine, it's usually not a big deal. However, if they consistently have dilute urine, it could be a sign of a kidney or metabolic disease that needs to be checked out.
pH & Chemical Composition
The pH level of urine shows how acidic or alkaline it is. A healthy pet's urine pH is typically between 6.5 and 7.0. If it's too acidic or alkaline, bacteria can grow, and crystals or stones can form.
Urine pH can change during the day due to food and medication. If one pH reading is abnormal, but everything else is normal, it's not a big deal. But if it's consistently off, the vet may want to investigate further.
Cells & Solid Material (Urine Sediment)
Some of the cells present in your pet's urine can include:
Red Blood Cells: Red blood cells may indicate bladder wall or kidney trauma or irritation. The technician will find red blood cells in the urine in pets with bladder or kidney infections, bladder stones, or interstitial cystitis. It may also be an early sign of cancer of the urinary tract.
White Blood Cells: White blood cells could indicate an infection or an inflammatory process in the bladder or kidney.
Protein: Protein should not be found in urine on a dipstick test. A positive protein in urine test may indicate a bacterial infection, kidney disease, or blood in the urine.
Sugar: Urine should not contain any sugar. The presence of sugar in the urine may signal the presence of Diabetes mellitus.
Ketones: If your pet tests positive for ketones in its urine, a Diabetes Mellitus workup will be performed. Ketones are abnormal byproducts that your pet's cells produce when they lack an adequate energy source.
Bilirubin: Bilirubinuria is an abnormal finding indicating that red blood cells in your pet's bloodstream are being destroyed faster than normal. It has been found in pets suffering from liver disease and autoimmune diseases. Remember that pets with blood in their urine due to a bladder infection can falsely stain the bilirubin pad on the dipstick, raising the possibility of a more serious liver problem.
Urobilinogen: Urobilinogen in urine indicates that the bile duct is open and bile can flow from the gallbladder into the intestine.
Blood: Blood in a dog's or cat's urine can indicate an infection, an inflammatory problem, or stones in the bladder or kidney. The dipstick can detect red blood cells or other blood components, such as hemoglobin or myoglobin, in your pet's urine.
Urine sediment should also be examined when conducting a urinalysis. Urine sediment is the material that settles to the bottom of a centrifuge after spinning a urine sample. Red blood cells, white blood cells, and crystals are the most common things found in urine sediment. Small amounts of mucus and other debris are frequently found in free-catch samples.
Crystals: Numerous types of crystals vary in size, shape, and color. Some crystals are one-of-a-kind and can aid in the diagnosis of a specific condition. In more common conditions, such as bladder infections, the crystals provide data that can influence how the disease is treated. Because crystals can form in urine after it has been collected, your veterinarian may want to examine a fresh sample right away.
Bacteria: The presence of bacteria as well as inflammatory cells in the sediment suggests that there is a bacterial infection somewhere in the urinary system. The urine should ideally be sent to a laboratory for culture and sensitivity testing to determine what types of bacteria are present and which antibiotic should be used to treat the infection.
Tissue Cells: While not necessarily a sign of disease, increased cellularity has been linked to several conditions, including urinary tract inflammation, bladder stones, prostate issues, and cancer. Catheterization samples frequently contain an increased number of tissue cells. If the cells appear abnormal, your veterinarian may advise you to have the sediment cytologically prepared. This enables a more in-depth examination of the tissue cells.