So, it’s not a pretty subject, but I’ve had a few people ask me how to collect a urine sample from their cat when the vet asks for one. There are many reasons why your veterinarian may want to analyze your cat’s urine. We routinely screen fecal samples and urine samples as part of many animals’ yearly health exams- meaning we’re not expecting to find anything wrong, and we’re confirming that they are healthy. However, when animals become sick and they present with certain symptoms, it may be in their best interest to analyze their urine.
What can a urinalysis tell us, and how do we perform it?
Illnesses such as renal disease and diabetes can be confirmed with a urinalysis- blood work alone is usually not enough for the veterinarian to make the diagnosis. It can also be helpful to analyze urine in suspected cases of urinary tract infections and bladder infections.
In my clinic, we use a three part system to analyze urine samples. We have dip sticks with 12 different reagents on them that we start with. This tells us how high the protein, pH, ascorbic acid, and glucose levels are, and if there is any blood, among other levels. We then use a clinical refractometer to get a reading that tells us how concentrated the urine is (this gives us an idea of how well the kidneys are functioning). Last we spin the urine in a centrifuge to separate any sediment that may be present. We then stain the sediment pellet and look at it under a microscope. If there is no sediment, we stain a drop of urine. When we look at the urine or sediment under the microscope, we’re mainly checking for what kind of bacteria and how much, if there are any white or red blood cells, and how many, and if any crystals (such as struvite and calcium oxalate crystals) are present and their numbers.
How do we collect urine?
If your vet asks you to bring a urine sample from home, they do not mean bring a clump of cat litter. We can’t do anything with that, and yes, I’ve had many people bring me bags of soiled litter. What they want you to do is have the cat void urine into an empty litter box; for you to catch the urine into a container when the cat squats to urinate; or, for you to use a litter analog to strain the urine off of.
At my clinic, we have a product called Plasti-Litter. It sort of looks like pieces of clumping cat litter but is made of tiny pieces of plastic. It’s sterile and won’t taint the sample, and cats feel like they’re using litter instead of an empty box. Once the cat has urinated, you can strain the liquid off of the Plasti-Litter and bring it to your vet.
Obtaining a urine sample after the cat has voided the urine is called a “free catch” method. It is ok for routine health screenings, but for very sick animals, or animals who are having repeated infections, it is best to have your veterinarian perform a cystocentisis. Urine that is obtained through the free catch method will not be as sterile, even if they urinate in a clean litterbox or you catch the urine in a clean container. There will always be foreign bacteria present, which will show up under the microscope.
A cystosentisis (often called a “cysto”) is when we palpate the bladder and insert a sterile, large gauge needle directly into the animal’s abdominal wall through the bladder to obtain a urine sample. This method results in the most accurate results for testing. You can ask your veterinarian to perform a culture and sensitivity test (C & S). Many offices (mine included) send the urine to an outside lab to analyze the urine. The culture half shows us if there is in fact an infection growing, and the sensitivity half shows us (if there is an infection) what kind of antibiotics to use for that particular bacteria.
Many times when we want to perform a cysto, the cat’s bladder is empty. We often ask clients to drop their cats off in the morning so that we can confine them without a litter box for a few hours, and sometimes give them fluids. This ensures that their bladder will be full.
Some important things to note:
Urinary tract infections are very uncommon in cats. Many cats will suffer from cystitis, which is inflammation of the bladder wall. Sometimes the cystitis will cause infection, but most of the time the cystitis is sterile. Many veterinarians neglect this fact and will send your cat home with antibiotics, which makes no sense when most of the time cats have sterile cystitis (I see this at my clinic all of the time). To determine which type of cystitis the cat has, a C&S has to be performed. It is worth it in the end to shell out the money, because treating sterile cystitis with antibiotics will most likely ensure that it will return.
Highly concentrated urine can cause bladder irritation, and feeding dry food only diets leads to very concentrated urine. Stress and diet are two major triggers of sterile cystitis. It is also a painful condition, and many veterinarians neglect to send patients home with pain medication.
Do you have a question about cat health? Email me at firstname.lastname@example.org