Veterinary diagnostic testing can be intimidating for pet owners, even simple testing such as urinalysis. Our vets in Ypsilanti are here to explain the purpose of this test and assure you that there's no need to worry if it's recommended for your pet.
Urinalysis for Dogs & Cats
A urinalysis is a straightforward test that examines the characteristics of the 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. Additionally, dogs showing signs like a sudden increase in water intake, frequent urination, or presence of blood in urine should also consider getting a urinalysis.
How is Urine Collected?
There are three main ways to collect urine from cats and dogs:
Cystocentesis: Urine is directly collected from the bladder using a sterile needle and syringe. This method ensures that the urine is not contaminated by debris from the lower urinary tract. It is ideal for evaluating the bladder and kidneys and detecting bacterial infection. Cystocentesis is slightly more invasive but effective when 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 known as the urethra.
Mid-stream Free Flow: In this method, your pet is allowed to urinate voluntarily, and a sample is collected into a sterile container while the pet urinates. This sample type is commonly known as a "free flow" or "free catch" sample. The benefits of this method are that it is entirely non-invasive, and pet owners can collect the 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 read within 30 minutes of collection to prevent changes in composition. Return samples to your vet as soon as possible. Timing of collection is usually insignificant except for testing for Cushing's disease or urine concentration, which should be done in the morning.
Color & Turbidity
The color of your pet's urine should range from pale yellow to light amber and appear clear or slightly cloudy. Dark yellow urine may indicate dehydration or a need for more water consumption. If the urine is not yellow and appears orange, red, brown, or black, this could be a sign of an underlying health issue, as it may contain substances not typically found in healthy urine.
An increase in turbidity or cloudiness in the urine may suggest the presence of cells or solid materials that should not be there. This could be due to the presence of blood, inflammatory cells, crystals, mucus, or debris. The sediment in the urine will need to be examined to determine the cause and if it is significant. significant.
Concentration, or the density of the urine, can be thought of as the level of thickness. When a kidney is healthy, it produces dense (concentrated) urine. On the other hand, if dogs and cats have watery (dilute) urine, it could 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 water is deficient, the kidneys reduce the amount of water lost in the urine, making it more concentrated.
It is normal for dogs and cats to have dilute urine occasionally, and it usually isn't a cause for worry. However, if a pet consistently has dilute urine, it could be a sign of an underlying kidney or metabolic disease that should be investigated further.
pH & Chemical Composition
The acidity of pet urine is indicated by its pH level, which typically ranges from 6.5 to 7.0 in healthy pets. If the pH level is either acidic (pH less than 6) or alkaline (pH greater than 7), it can promote bacterial growth and lead to the formation of crystals or stones. It's normal for urine to vary throughout the day, especially after consuming certain foods or medications. There's no need to worry if a single pH reading is the only abnormality in a urinalysis. However, if the pH level consistently deviates from the normal range, it may be necessary to consult a veterinarian for further investigation.
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: The presence of bilirubin in your pet's urine may indicate faster-than-normal destruction of red blood cells in their bloodstream. This anomaly is commonly observed in pets suffering from autoimmune diseases and liver disease. It is important to note that a bladder infection can also result in blood in your pet's urine, leading to false staining of the bilirubin pad on the dipstick. This may cause unnecessary worry about your pet's liver health, and further tests may be necessary to rule out other potential causes.
Urobilinogen: Urobilinogen in urine indicates that the bile duct is open and bile can flow from the gallbladder into the intestine.
Blood: If you notice blood in your pet's urine, it may indicate an infection, inflammation, or bladder/kidney stones. A dipstick test can detect red blood cells or other blood components like hemoglobin or myoglobin in their urine. It's important to examine the urine sediment as well, which is the material that settles at the bottom of a centrifuge after spinning a urine sample. Urine sediment typically contains red blood cells, white blood cells, and crystals, and sometimes small amounts of mucus and debris in free-catch samples.
Red Blood Cells: Red blood cells may indicate bladder wall or kidney trauma or irritation. The technician will find red blood cells in the urine in pets 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.
Crystals: A wide range of crystals differ in size, shape, and color. Certain crystals are unique and can assist in identifying a particular ailment. In more prevalent ailments like bladder infections, these crystals provide crucial information that can impact the treatment plan. Since crystals can develop in urine after it's been collected, your veterinarian may request a fresh sample for immediate examination.
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: Although not always indicative of illness, heightened cellularity has been associated with various conditions such as inflammation of the urinary tract, bladder stones, prostate complications, and cancer. Catheterization samples often exhibit an excess of tissue cells. If these cells exhibit anomalous characteristics, it's recommended that you seek your veterinarian's advice on having sediment cytologically prepared. This will allow for a more thorough analysis of the tissue cells.