When it comes to monitoring the health of your cat or dog, your vet may occasionally recommend various types of diagnostic tests. Today, our Westfield vets talk about urinalysis for dogs and cats, what the results will show your vet and how these tests can help your pet.
Pet Diagnostics: Urinalysis For Dogs & Cats
One of the diagnostic tests that your vet may commonly perform on your pet is a urinalysis. This can help show your vet the physical and chemical properties of urine.
This type of diagnostic test is primarily used to help evaluate the health of the kidneys and urinary system of your pet, as well as to reveal issues with other organ systems. Dogs and cats that are 8 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.
Methods for Collecting the Urine Sample
There are 3 methods of collecting urine to be used for pet urinalysis. These are:
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 can allow the pet parent to collect this sample in the comfort of their own home.
What are the main parts of pet urinalysis?
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.
When your pet is in need of a urinalysis then the samples should be collected bo more than 30 minutes before being read 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. If your vet is examining the sample for Cushing's disease or evaluating your pet's ability to concentrate urine, they will likely ask for a urine sample taken first thing in the morning.
The Color & Turbidity of the Urine
Urine that ranges from pale yellow to light amber in color and is clear to slightly cloudy. Dark yellow urine indicates that your cat or dog may be dehydrated and should increase their fluid intake. Urine that is not yellow (for example, orange, red, brown, or black) has the potential to contain substances that are detrimental to the health of your pet and may indicate an underlying health condition or concern.
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 this sediment and determine whether it indicates any concerns regarding the health of your pet.
Urine Concentration or Density
The concentration of the urine is also a strong indicator of the health of your dog or cat's kidneys. A healthy kidney produces dense (concentrated) urine, whereas watery (dilute) urine in dogs and cats 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 you are consistently noticing diluted urine from your pet, it may not always be 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 acidity levels of your pet's urine are indicated by the pH. 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 concern. If your pet is frequently experiencing abnormal pH results then your vet will likely recommend further testing to ensure that there are no underlying health concerns.
Amount of Sediment in the Urine
There are a number of different cells that can be found within your pet's urine including:
Protein: When a dipstick test is performed, one thing that should not be found is proteins. A positive protein in urine test may indicate a bacterial infection, kidney disease, or blood in the urine.
Sugar: There should never be any sugars present in your cat or dog's urine. The presence of sugar in the urine may signal the presence of Diabetes mellitus.
Ketones: If your pet tests are positive for ketones in its urine, a Diabetes Mellitus workup will be performed. Ketones are abnormal byproducts that your pet's cells produce when there is no other energy source being resented to the body.
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: When there are concerns such as trauma or irritation to the bladder wall or kidneys then red blood cells may be present. 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: If your vet mentions white blood cells being found in the urine sample then this could indicate an infection or an inflammatory process in the bladder or kidney.
Crystals: Crystals can be any one of a number of types that vary in size, shape, and color. Certain crystals are unique which 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 suggest an examination of a new, fresher sample of your pet's urine.
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 the appearance of tissue cells is not always 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 allows your veterinarian to perform 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.