Urinalysis (urine test) as a diagnostic tool in the diagnosis of urinary tract infection in Dogs & Cats

October 5, 2023

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Urinalysis (urine test) as a diagnostic tool in the diagnosis of urinary tract infection in Dogs & Cats

Significance of Urine Analysis in the Diagnosis of Urinary Tract Infections.

A urinalysis (also known as a urine test) is a test that examines the visual, chemical and microscopic aspects of your urine (pee). It can include a variety of tests that detect and measure various compounds that pass through urine using a single sample of urine.

Vets often use urinalysis to screen for or monitor certain common health conditions, such as liver disease, kidney disease and diabetes, and to diagnose urinary tract infections (UTIs).

While several different aspects of health can be tested with a urine sample, your vets will choose which tests to order under a urinalysis depending on symptoms and situation.

Urinary tract infection (UTI) refers to condition in the urinary bladder (sometimes also involving the kidneys) caused by infection, usually with bacteria. Bacterial urinary tract infections occur in approximately 14 % of dogs during their life time (Westdropp et al., 2012). It has been estimated that as many as 10% of all canine patients seen by veterinarians for any reason have UTI in addition to the problems for which they are presented (Cetin et al., 2003). There are chances of misinterpretation of diseases due to overlapping nature of clinical signs of this disease as well asinappropriate diagnostic tools and methods. Urinary tract infections are one of the leading causes for prostatic diseases in male dogs and even can further lead to renal failure, if untreated. Keeping in view, the importance of physio-chemical andmicroscopic changes of urine in canine patient suffering from urinary tract infection and its importance in diagnosis, the present study was planned to assess the typical changes associated with UTIs in urine of dogs.

Urinalysis is a simple, rapid, non-invasive, economical laboratory test that can provide insight into urinary tract infection in dogs. It can be used as a tool not only for tentative diagnosis but also would help clinician to initiate the palliative treatment before culture results are available with the physician so that damage can be stopped.

The evaluation of both normal and abnormal urine contents is known as a urine analysis. For veterinarians, it is a simple, affordable, and crucial first diagnostic procedure. It aids in the diagnosis of urinary tract infection and may be helps in the starting of empirical therapy.

Urinary tract infection (UTI) is the microbial colonisation of the urinary system or any urinary tract organ. Apart from the distal urethra, which has a normal bacterial flora. The most prevalent infectious disease in dogs is assumed to be urinary tract infection. According to estimates, up to 10% of all canine patients who visit vets for whatever reason also have UTI in addition to the issues they are there for . The origin of UTIs can be bacterial, fungal, algal, protozoal, and very rarely viral. Urinary tract infection (UTI) of bacterial origin is the most common infectious disease of dogs, affecting 14% of all dogs during their lifetime . Diagnosing a bacterial UTIs required a positive urine culture, isolation and identification of the organism and other tests may also be used in the diagnosis such as urine analyses, complete blood counts (CBC), chemistry profiles, rectal examinations, abdominal radiographs, abdominal ultrasounds, contrast radiology, cystoscopy with bladder wall culture tests and prostatic washes . Urinalysis is the clinical laboratory’s third major diagnostic screening test. It is an important check for the occurrence, extent, and length of urinary tract diseases. It is the best way to diagnose kidney dysfunction before renal failure happens . If left untreated, urinary tract infections are one of the most common causes of prostatic illnesses in male dogs and may potentially result in renal failure.

Urinalysis is the clinical laboratory’s third major diagnostic screening test, only preceded by serum/plasma chemical profiles and complete blood count analysis . It is an important check for the occurrence, extent, and length of urinary tract diseases. It can also be useful for physical health, physiological condition, fluid balance, systemic illness, and harmful insults . It is the best way to diagnose kidney dysfunction before renal failure happens . Urinalysis includes evaluation of physical characteristics, biochemical parameters, microscopic sediment, and enzyme estimation . Urinary chemical strip, semi-automatic, and automatic urine analyzer specifically for veterinarians are already in place. Proper urinalysis can help in the detection of various metabolic diseases such as ketosis and diabetes by estimating glucose and ketones concentration, liver abnormalities on bilirubin estimation, and intravascular hemolysis on increased hemoglobin concentration . Urine has become one of the most accessible bio-fluid as it can be obtained non-invasively in large quantities . In veterinary medicine, it has gained little attention .

A urinalysis is a simple test that looks at a small sample of your urine. It can help find problems that need treatment, including infections or kidney problems. It can also help find serious diseases in the early stages, like kidney disease, diabetes, or liver disease. A urinalysis is also called a “urine test.”

A urine test can include three parts:

Visual exam. The urine will be looked at for color and clearness. Blood may make urine look red or the color of tea or cola. An infection may make urine look cloudy. Foamy urine can be a sign of kidney problems.
Microscopic exam. A small amount of urine will be looked at under a microscope to check for things that do not belong in normal urine that cannot be seen with the naked eye, including red blood cells, white blood cells (or pus cells), bacteria (germs), or crystals (which are formed from chemicals in the urine and may eventually get bigger and become kidney stones).
Dipstick test. A dipstick is a thin, plastic stick with strips of chemicals on it. It is dipped into the urine. The strips change color if a substance is present at a level that is above normal. . Some of the things a dipstick examination can check for include:
- Acidity (pH) is a measure of the amount of acid in the urine. A pH that is above normal may be a sign of kidney stones, urinary infections, kidney problems, or other disorders.
- Protein is an important building block in the body. Everyone has protein in their blood. But it should only be in your blood, not your urine. Your kidneys play a role in this process. Healthy kidneys remove waste products and extra water from your blood, but leave behind the things your body needs, like protein. When kidneys are injured, protein leaks into your urine. Having protein in your urine suggests that your kidney’s filtering units are damaged by kidney disease.
- Glucose (sugar) is usually a sign of diabetes.
- White blood cells (pus cells) are signs of infection.
- Bilirubin is a waste product from the breakdown of old red blood cells. It is normally removed from the blood by the liver. Its presence in the urine may be a sign of liver disease.
- Blood can It can be a sign of an infection, a kidney problem, certain medicines, or even heavy exercise. Finding blood in the urine requires further testing. It does not mean you have a serious medical problem.

A urinalysis can help to detect many diseases before you feel symptoms. Finding and treating a problem early can help keep serious diseases from getting worse.

Urinalysis for Dogs & Cats

A urinalysis is a simple diagnostic test for dogs and cats that helps your vet to determine the physical and chemical properties of your pet’s urine. It is primarily used to evaluate the health of the kidneys and urinary system, but it can also reveal issues with other organ systems. All pets eight years of age and older should have a yearly urinalysis. A urinalysis may also be recommended if your pet has increased water intake, increased frequency of urination, or visible blood in the urine.

How to Collect Your Pet’s Urine

When it comes to collecting urine for cats or dogs there are 3 main approaches:

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 as well as 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 voluntarily, and 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 the pet’s urine sample at home.

What Your Dog or Cat’s Urinalysis Results Mean

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) present in the urine using a microscope.

Urine samples should be read within 30 minutes of the collection because other factors (such as crystals, bacteria, and cells) can alter the composition (dissolve or multiply). If you collect a urine sample at home, please return it as soon as possible to your veterinary clinic. Unless we are evaluating your pet’s ability to concentrate urine, or screening for Cushing’s disease, the actual timing of urine collection 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 that 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. The sediment will be examined to determine what is present and whether it is significant.

Concentration

Consider concentration to be the density of the urine. A healthy kidney produces dense (concentrated) urine, whereas dilute urine in dogs and cats (watery urine) may indicate 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.

If a dog or cat passes dilute urine from time to time, it 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 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 caused 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 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 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 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.

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.

How Does a Urinalysis Work?

There are three ways to analyze urine, and your test might use all of them.

One is a visual exam, which checks the color and clarity. If your pee has blood in it, it might be red or dark brown. Foam can be a sign of kidney disease, while cloudy urine may mean you have an infection.

A microscopic exam checks for things too small to be seen otherwise. Some of the things that shouldn’t be in your urine that a microscope can find include:

Red blood cells
White blood cells
Bacteria
Crystals (clumps of minerals, a possible sign of kidney stones)

The third part of urinalysis is the dipstick test, which uses a thin plastic strip treated with chemicals. It’s dipped into your urine, and the chemicals on the stick react and change color if levels are above normal. Things the dipstick test can check for include:

Acidity, or pH. If the acid is abnormal, you could have kidney stones, a urinary tract infection (UTI), or another condition.
Protein. This can be a sign your kidneys aren’t working right. Kidneys filter waste products out of your blood.
Glucose. A high sugar content is a marker for diabetes.
White blood cells. These are a sign of infection or inflammation, either in the kidneys or anywhere else along your urinary tract.
Nitrites. This means that there is an infection with certain kinds of bacteria.
Bilirubin. If this waste product, which is normally eliminated by your liver, shows up, it may mean your liver isn’t working properly.
Blood in your urine. Sometimes this is a sign of infections or certain illnesses.

Why Is Urinalysis Done?

You may have a urinalysis as part of a routine check of your pets overall health, like during your yearly physical. Urinalysis is one way to find certain illnesses in their earlier stages. They include:

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.

Compiled & Shared by- This paper is a compilation of groupwork provided by the

Team, LITD (Livestock Institute of Training & Development)

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Reference-On Request.

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EXAMINATION OF URINE IN ANIMALS