Understanding a bit about the tests your vet recommends can help you get a better understanding of your pet's overall health. Today, our Westminster vets explain how urinalysis helps us to provide more targeted treatments for your pet's symptoms.
Urinalysis for Dogs & Cats
A urinalysis is a simple diagnostic test for dogs and cats that provides your veterinarian with insights into the physical and chemical properties of your pet's urine. This diagnostic test is primarily used to evaluate the health of your dog or cat's kidneys and urinary system, but it can also reveal issues with other organ systems.
Many vets recommend that all pets over 8 years of age have yearly urinalysis testing done to catch developing health problems before symptoms develop. A urinalysis may also be recommended if your dog or cat has begun to drink excessive amounts of water, is experiencing an increased frequency of urination, or has visible blood in the urine.
How Your Pet's Urine is Collected for Urinalysis
Many pet parents are nervous about collecting a urine sample from their dog or cat, but the process is often far easier than you may expect. There are three main approaches to collecting urine samples from our four-legged friends:
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 for 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 very narrow sterile catheter is inserted into the bladder through the lower urinary passage (called the urethra).
Mid-Stream Free Flow: The pet urinates like normal, and a sample is collected into a sterile container. 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 the pet's urine sample at home simply by slipping a clean container under their pet mid-stream.
Understanding Urinalysis Results for Dogs & Cats
There are four main parts to a urinalysis:
- Assess appearance: color and turbidity (cloudiness).
- Measure the concentration or density of the urine. (i.e. concentrated or dilute urine in dogs and cats).
- 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.
Ideally, urine samples should be read within 30 minutes of the 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, please drop it off at our veterinary clinic as soon after collection as possible.
Unless we are evaluating your pet's ability to concentrate urine, or screening for Cushing's disease, the actual time of day that you collect the urine is usually insignificant. But if we are screening your pet for Cushing's disease or evaluating your dog or cat's ability to concentrate urine, we want a urine sample taken first thing in the morning.
Color & Turbidity
Urine ranges from pale yellow to light amber in color and is clear to slightly cloudy. Dark yellow urine usually indicates that the pet needs to drink more water or is dehydrated. Urine that is not 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. Turbidity increases when there is blood, inflammatory cells, crystals, mucus, or debris present. Your vet will examine the sediment 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 dilute urine in dogs and cats (watery urine) may indicate an underlying disease.
If there is an excess of water in the body, the kidneys allow it to pass out in the urine, making the urine more watery or dilute. If there is not enough water, the kidneys reduce the amount of water lost in the urine, making it more concentrated.
Occasional dilute urine in dogs and cats is not necessarily a cause for concern. However, 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 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. However, 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
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 Diabetes mellitus.
Ketones: If your animal companion 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 that indicates that the red blood cells are being destroyed at a faster-than-normal rate. 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.
Bacteria: The presence of bacteria and 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.
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 likely 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.
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.