A urinalysis test can help detect several conditions and diseases your cat or dog may have. Today, our Hattiesburg vets discuss the importance of regular urinalysis testing for pets.
Urinalysis for Pets
A urinalysis is a straightforward diagnostic test that assesses urine's physical and chemical properties. Its primary purpose is to evaluate the health of the kidneys and urinary system, but it can also detect issues with other organ systems. All senior pets aged eight years and older should undergo a yearly urinalysis. Additionally, a urinalysis may be recommended if your pet experiences increased water intake, more frequent urination, or visible blood in the urine.
How to collect a pet's urine?
There are three main ways to collect urine from cats and dogs:
Cystocentesis: Urine is collected from the bladder using a sterile needle and syringe. The benefit of cystocentesis is that the urine is not contaminated by debris from the lower urinary tract. This sample is ideal for evaluating the bladder and kidneys as well as detecting bacterial infection. The procedure is slightly more invasive than others and is only useful if the pet's bladder is full.
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 narrow sterile catheter is inserted into the bladder through the lower urinary passage (called the urethra).
Mid-stream Free Flow: The pet urinates voluntarily, and a sample is collected into a sterile container as it does so. This type of sample is frequently referred to as a "free flow" or "free catch" sample. This method is beneficial because it is completely noninvasive, and the pet owner can collect a 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.
Urine samples should be read within 30 minutes of the collection because other factors (such as crystals, bacteria, and cells) can alter the composition (dissolve or multiply). If you collect a urine sample at home, please return it to your veterinary clinic immediately. Unless we are evaluating your pet's ability to concentrate urine, or screening for Cushing's disease, the actual timing of urine collection is usually insignificant. But if we are screening for Cushing's disease or evaluating your pet's ability to concentrate urine, we want a urine sample taken first thing in the morning.
Color & Turbidity
Urine can range from pale yellow to light amber in color and should be clear to slightly cloudy. If the urine is dark yellow, it could mean that the pet needs to drink more water or might be dehydrated. Unusual colors such as orange, red, brown, or black may indicate an underlying health issue as they may contain substances not normally found in healthy urine.
Increased cloudiness in the urine suggests the presence of cells or other solid materials. Cloudiness can result from the presence of blood, inflammatory cells, crystals, mucus, or debris. The sediment will be examined to determine what is present and whether it is significant.
Concentration
Concentration is the density of the urine. A healthy kidney produces dense (concentrated) urine, whereas watery (dilute) urine in dogs and cats may indicate underlying disease.
If the body has an excess of water, the kidneys allow it to pass out in the urine, making it more watery or dilute. If water is deficient, the kidneys reduce the amount of water lost in the urine, making it more concentrated.
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, an underlying kidney or metabolic disease may require further investigation.
pH & Chemical Composition
The pH level of the urine indicates its acidity. The pH of urine in healthy pets is usually between 6.5 and 7.0. If the pH is acidic (pH less than 6) or alkaline (pH greater than 7), bacteria can thrive, and crystals or stones can form.
Normal variations in urine occur throughout the day, especially when certain foods and medications are consumed. If the rest of the urinalysis is normal, a single urine pH reading is not a cause for concern. If it is consistently abnormal, your veterinarian may wish 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 pets' urine 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.
Remember to examine the urine sediment as part of the urinalysis process. Urine sediment is the material that settles at the bottom of a centrifuge after spinning a urine sample. The most common components found in urine sediment include red blood cells, white blood cells, and crystals. Small amounts of mucus and other debris are often found in free-catch samples.
Crystals: Numerous types of crystals vary in size, shape, and color. Some crystals are unique and can aid in diagnosing 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 being collected, your veterinarian may want to examine a fresh sample immediately.
Bacteria: The presence of bacteria and inflammatory cells in the sediment suggests a bacterial infection 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.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding people or pets. If you are concerned about your pet's health, contact your veterinarian right away for diagnosis and treatment.