We at Best Friends Veterinary Hospital strongly believe in educating our clients to help them be the best pet owners they can be. In order to help you make the best choices for your pet's medical care, our Poway veterinarians will talk to you today about urinalysis for dogs and cats as well as how to interpret your pet's urinalysis results.
Why would my vet recommend a urinalysis?
A urinalysis is a simple diagnostic test that determines the physical and chemical properties of urine. It is primarily used to evaluate the health of the kidneys and urinary system, but it can also reveal issues with other organ systems. All pets eight years of age and older should have a yearly urinalysis. A urinalysis may also be recommended if your pet has increased water intake, increased frequency of urination, or visible blood in the urine.
How is urine collected?
There are three main ways to collect urine from cats and dogs:
Cystocentesis: I draw urine from the bladder using a sterile needle and syringe. Cystocentesis prevents lower urinary tract debris from contaminating the urine, which is advantageous. The sample is perfect for diagnosing bacterial infection and evaluating the bladder and kidneys. The procedure only benefits if the pet's bladder is full and is slightly more invasive than others.
Catheterization: Catheterization is a less invasive method of extracting urine from the bladder in dogs and is an excellent choice when a voluntary sample is unavailable, particularly in male dogs. A very narrow sterile catheter is inserted into the bladder through the lower urinary passage (called the urethra).
Mid-stream Free Flow: The animal urinates voluntarily, and as it does so, a sample is taken and placed in a sterile container. The terms "free flow" and "free catch" are frequently used to describe this kind of sample. This approach has the advantages of being completely non-invasive and allowing the pet owner to collect the urine 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.
You should read urine samples within 30 minutes of collection because other factors like crystals, bacteria, and cells can change their composition (dissolve or multiply). Please send any urine samples you collect at home to your local veterinary clinic as soon as possible. We typically don't consider the precise timing of urine collection important unless we are assessing your pet's capacity to concentrate urine or performing a Cushing's disease screening. However, if we are checking for Cushing's disease or assessing your pet's capacity to concentrate urine, we need to take a urine sample first thing in the morning.
Color & Turbidity
The urine is clear to slightly cloudy and ranges in color from pale yellow to light amber. The animal typically needs to drink more water or is dehydrated if its urine is dark yellow. If the urine is orange, red, brown, or black in color instead of yellow, it may indicate a health problem. Healthy urine typically does not contain substances found in such urine.
Increased turbidity or cloudiness in the urine indicates the presence of cells or other solid materials. Turbidity increases when there is blood, inflammatory cells, crystals, mucus, or debris present. The sediment will be examined to determine what is present and whether it is significant.
Consider concentration to be the density of the urine. A healthy kidney produces dense (concentrated) urine, whereas watery (dilute) urine in dogs and cats may indicate underlying disease.
The kidneys expel extra water in the body through urine, which dilutes the urine and makes it more watery. The kidneys increase the concentration of urine by reducing the amount of water lost in the urine when there is a lack of water.
If a dog or cat passes dilute urine from time to time, it is not necessarily a cause for concern. If a pet continuously passes dilute urine, there may be an underlying kidney or metabolic disease that requires further investigation.
pH & Chemical Composition
The pH level of urine reveals its acidity. Pets that are healthy typically maintain a urine pH level of 6.5 to 7.0. In an acidic (pH less than 6) or alkaline (pH greater than 7) environment, bacteria flourish and crystals or stones form. Throughout the day, urine typically varies, especially after consuming certain foods and medications. If the rest of the urinalysis is normal, a single urine pH reading is unimportant. If your pet consistently behaves abnormally, your veterinarian might want to investigate it further.
Cells & Solid Material (Urine Sediment)
Some of the cells present in the urine can include:
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: An abnormal finding called bilirubinuria shows that the red blood cells in your pet's bloodstream are depleting more quickly than usual. It has been discovered in animals with autoimmune and liver diseases. It's important to keep in mind that pets with blood in their urine from a bladder infection may mistakenly stain the bilirubin pad on the dipstick, raising the possibility of a more severe liver condition.
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: 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.
Red Blood Cells: Red blood cells may indicate bladder wall or kidney trauma or irritation. In pets with bladder or kidney infections, bladder stones, or interstitial cystitis, the technician will find red blood cells in the urine. 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.
Crystals: Crystals come in a wide variety of sizes, shapes, and colors. Unique crystals can help with the diagnosis of a particular condition. The crystals offer information that can affect how a disease is treated in more prevalent conditions like bladder infections. Your veterinarian may want to examine a fresh sample of urine right away because crystals can develop in urine after it has been collected.
Bacteria: It is possible that there is a bacterial infection somewhere in the urinary system given the presence of bacteria and inflammatory cells in the sediment. In order to identify the types of bacteria present and the appropriate antibiotic to treat the infection, the urine should ideally be sent to a laboratory for culture and sensitivity testing.
Tissue Cells: Increased cellularity has been connected to a number of diseases, including cancer, prostate problems, bladder stones, inflammation of the urinary tract, and stones in the bladder. Samples taken during catheterization frequently have more tissue cells than usual. Your veterinarian might suggest having the sediment cytologically prepared if the cells seem abnormal. This makes it possible to look at the tissue cells in greater detail.
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.