Regular urinalysis testing for pets is important as it can help detect several conditions and diseases your cat or dog may have. Our Los Angeles County vets today discuss the significance of this test.
Urinalysis for Pets
A urinalysis determines urine's physical and chemical properties as a straightforward diagnostic test. It evaluates kidney and urinary system health while potentially uncovering issues in other organ systems. An annual urinalysis is strongly advised for senior pets aged eight and older. Additionally, a urinalysis may be recommended if your pet exhibits increased water intake, heightened urination frequency, or visible blood in the urine.
Collecting a Urine Sample
Three main methods exist for collecting 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 and detecting bacterial infection. The procedure is slightly more invasive than others and is only helpful 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 the pet urinates. This type of sample is frequently called a "free flow" or "free catch" sample. The benefits of this method include the fact that it is entirely non-invasive and that 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) in the urine using a microscope.
Read urine samples within 30 minutes of collection because other factors, such as crystals, bacteria, and cells, can alter the composition by dissolving or multiplying. If you collect a urine sample at home, return it to your veterinary clinic promptly. The timing of urine collection is typically insignificant unless we evaluate your pet's ability to concentrate urine or screening for Cushing's disease. However, to screen for Cushing's disease or evaluate your pet's ability to concentrate urine, take a urine sample first thing in the morning.
Color & Turbidity
The urine should be pale yellow, light amber, and clear to slightly cloudy. If the urine appears dark yellow, it suggests the pet needs more water or is dehydrated. Unusual colors such as orange, red, brown, or black may signal the presence of substances not normally found in healthy urine, indicating a potential underlying health issue.
The presence of cells or other solid materials in the urine causes increased turbidity or cloudiness. Turbidity rises when blood, inflammatory cells, crystals, mucus, or debris are present. The sediment will be examined to identify the substances present and assess their significance.
Consider urine density as the concentration level. A healthy kidney generates concentrated urine, while dogs and cats with watery urine may indicate underlying disease.
When the body has excess water, the kidneys expel it in the urine, resulting in a more dilute composition. Conversely, if water is scarce, the kidneys minimize water loss in the urine, leading to a more concentrated form.
Intermittent dilute urine in dogs or cats is not necessarily alarming. However, continuous dilute urine may signal an underlying kidney or metabolic disease, warranting further investigation.
pH & Chemical Composition
The acidity of urine is indicated by its pH level. Healthy pets typically maintain a urine pH between 6.5 and 7.0. When the pH is below 6, indicating acidity, or above 7, indicating alkalinity, bacteria can thrive, forming crystals or stones.
Throughout the day, variations in urine composition are normal, particularly in response to specific foods and medications. If a single urine pH reading is abnormal, but the rest of the urinalysis is normal, it is not a cause for concern. However, if the abnormal pH readings persist, your veterinarian may opt 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.
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 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, 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.