Your vet can perform a urinalysis to determine whether your cat or dog may have a health condition or disease that needs treatment. Here, our South Wilton veterinarians explain why regular urinalysis testing for pets is a critical part of their care.
Urinalysis for Pets
A urinalysis is a simple diagnostic test that helps determine the chemical and physical properties of your pet's urine. Though our veterinarians most often use this test to assess the health of a cat or dog's kidneys and urinary system, it can also uncover issues with other organ systems.
All senior pets eight years of age and older should have a urinalysis done every year. Your veterinarian may also recommend a urinalysis if your pet is urinating more frequently or drinking more water than usual, or if blood has been seen in their urine.
Collecting a Urine Sample
There are three main methods of collecting urine from cats and dogs:
Mid-Stream Free Flow - Your pet urinates voluntarily and the sample is collected into a sterile container. Often referred to as a "free flow" or "free catch" sample, this method is completely non-invasive and allows the pet owner to collect a urine sample at home.
Cystocentesis – A sterile needle and syringe will be used to collect urine from the bladder. This method does not contaminate urine with debris from the lower urinary tract, so your vet will be able to evaluate the bladder and kidneys easily. It can also be used to detect bacterial infections. Keep in mind that this procedure is slightly more invasive than others and should only be done if the pet's bladder is full.
Catheterization – If a voluntary sample is unavailable, this less invasive method of extracting urine from a dog's bladder is an excellent option, especially for male dogs. The vet will insert a very narrow sterile catheter into the bladder through the lower urinary passage (urethra).
Understanding Urinalysis Results
There are four primary aspects of a urinalysis:
- Assess the appearance of the urine, including its color and cloudiness (also referred to as turbidity).
- Measure the concentration (density) of the urine.
- Measure pH (acidity) and analyze the urine's chemical composition.
- Use a microscope to examine the cells and solid material (urine sediment) in the urine.
Urine samples should be analyzed no more than 30 minutes after they are collected, since other factors (such as cells, bacteria, and crystals) can change its composition (causing multiplication or dissolution of these).
If you collect a urine sample from your pet at home, please return it to our animal hospital as soon as possible. Unless we are evaluating your pet's ability to concentrate urine, or screening for Cushing's disease, the actual timing of urine collection is insignificant. However, if we are screening for Cushing's disease or evaluating your pet's ability to concentrate urine, collecting a sample first thing in the morning is ideal.
Color & Turbidity
Healthy urine is light amber, or pale yellow in color. It may be clear or slightly cloudy. If your pet's urine is dark yellow, it typically means they need to drink more water or that they are dehydrated. Urine that's not yellow (for example, brown, orange, red, or black) may contain substances not normally found in healthy urine and may be indicative of an underlying health condition.
Increased cloudiness or turbidity in your pet's urine indicates that cells or other solid materials are present. When inflammatory debris, cells, crystals, mucus, or blood are present, turbidity will increase. Your vet will examine the sediment to determine which of these elements are present and whether they are significant.
Concentration
Concentration can best be described as the density of the urine. If your pet's kidneys are healthy, they will produce dense (concentrated) urine, where as watery or dilute urine in cats and dogs can indicate underlying disease.
If the body contains too much water, the kidneys will allow the water to pass through the urine. This causes the urine to become more watery or dilute. If there is an insufficient amount of water in the body, the kidneys reduce the amount of water lost through the urine, which will make it more concentrated.
A cat or dog passing dilute urine from time to time is not necessarily a cause for concern. However, if your pet frequently passes dilute urine, this may be a sign of underlying kidney or metabolic disease that will require further investigation an management.
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. 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.
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 that indicates that red blood cells in your pet's bloodstream 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.
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 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.
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.
