Veterinary diagnostic testing of any kind can be scary for pet owners even simple testing such as urinalysis. Our Hattiesburg and Wiggins vets are here to tell you what this test does and why you shouldn't worry if it's recommended for your pet.
Urinalysis for Dogs & Cats
A urinalysis is a simple diagnostic test that determines the physical and chemical properties of urine. This diagnostic test is most often used to check your pet's kidneys and urinary system but it can also reveal issues with other organ systems. Every pet eight years of age and older should have a urinalysis performed annually. Dogs who have increased their water intake suddenly, increased frequency of urination, or bloody urine will also be recommended to have a urinalysis.
How is Urine Collected?
There are three main ways to collect urine from cats and dogs:
Cystocentesis: Urine is collected directly from your dog or cat’s bladder using a sterile needle or syringe. The benefit of cystocentesis is that your pet’s urine is not contaminated by debris from the lower urinary tract. This kind of sample is ideal for evaluating the bladder and kidneys and detecting bacterial infection. The procedure is a little more invasive than others, and is only useful if the dog or cat’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 very narrow sterile catheter is inserted into the bladder through the lower urinary passage known as the urethra.
Mid-stream Free Flow: For this method, your pet can urinate voluntarily, and when they do, a sample is collected into a sterile container as the pet urinates. This type of sample is frequently referred to as a "free flow" or "free catch" sample. The benefits of this method include the fact that it is completely non-invasive and that the pet owner can collect a urine sample at home.
What Your Vet Looks For In A Urinalysis
There are four main things that are looked for by your vet when performing a urinalysis:
- Assess the appearance including 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 examined within 30 minutes of collection, This is because other factors (like crystals, bacteria, and cells) can alter the composition (by dissolving or multiplying). If you collect a urine sample at home, please return it ASAP to your veterinarian. Unless we’re evaluating your dog or cat’s ability to concentrate urine, or screening for Cushing's disease, when you collect the urine 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 ranges in color from pale yellow to light amber, and is clear to slightly cloudy. Dark yellow urine can mean that your pet needs to drink more water or that they’re dehydrated. Urine that isn’t yellow (for example, orange, red, brown, or black) may contain substances that are not normally found in healthy urine and could indicate an underlying health issue.
Increased turbidity or cloudiness in the urine indicates the presence of cells or other solid materials that should not be there. 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.
If there is too much water in the body, the kidneys allow the water to pass in the urine. But this makes the urine more watery or dilute. If there is not enough water, the kidneys reduce the amount of water lost in the urine. This makes the urine more concentrated.
Dilute urine in dogs and cats is normal from time to time and 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 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 fluctuations in urine occur throughout the day, especially when a pet eats certain foods and medications. If the rest of the urinalysis is normal, a single urine pH reading is not a cause for worry. If it is consistently abnormal, your veterinarian may wish to investigate 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 need to 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 that normally indicates that red blood cells in your dog or cat’s bloodstream are being destroyed at a faster-than-normal rate. It has been found in cats and dogs suffering from liver disease and autoimmune diseases. It’s important to remember that blood in your pet's urine resulting from a bladder infection can cause false staining of the bilirubin pad on the dipstick, which may cause concern that your pet has serious liver problems. More testing may be required to rule out any other causes.
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.
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: There are numerous types of crystals that 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.