Cat UTI's, Bladder Stones, and Blockages

Posted by Chris Vanderhoof, DVM, MPH on Sep 7, 2020 8:00:00 AM
Chris Vanderhoof, DVM, MPH

Cat UTI Problems

One of the great things about cats is that they are independent and fairly self-sufficient.

Give them some food and a litter box and they’re pretty well taken care of. They tend to amuse themselves even when toys are not available, they don’t require walks, and they even bathe themselves!

 

I rescued my three cats together as littermates just before I started veterinary school, so we were happily stuck with each other already. 

 

But with the very long hours in vet school with little opportunity to go home during the day and sometimes staying at school until very late at night (or even early the next morning) studying, I was grateful for having cats because I knew my three furry friends would be just fine until I got home. 

 

Or at least that was the case until, coming home late one night, I found some spots of bloody urine in my bathtub. 

 

It’s a scenario many kitty parents can identify with. The litterbox is where the pee and poop go. Finding either out of place just isn’t cool. And seeing blood? Bad news.

 

In this article, we’re going to discuss urinary tract issues in cats, including urinary tract infections in cats and other causes of urinary tract pain and inflammation, by dividing these conditions into two main categories.

 

We’ll also discuss a veterinarian's approach to cat UTI treatment, as well as for these other conditions, and some preventive health tips to try to keep your kitty happy and healthy. 

 

Cat UTI Infection

Signs of Urinary Tract Disease

In this article, we’re focusing on disease of the lower urinary tract itself, which includes the bladder and urethra.

 

There is a collection of signs typically seen in cats anytime we have an issue affecting these structures.

 

I Gotta Go!: Frequent Need to Pee

A frequent urgency to urinate, which we term pollakiuria, is a hallmark of urinary tract disease. A kitty that is returning to the box multiple times over the course of an hour, or at the very least more often than usual, is typical.

 

Any cause of discomfort or inflammation in the urinary tract will create a sensation of the need to urinate constantly. Any human who has had a UTI will tell you how uncomfortable it is.

 

Pee Outside of the Box

The litterbox is where the pee goes. It’s always stressful and disconcerting to find pee on the carpet, piles of clothes, or even more frustrating, literally on the floor right next to the box.

 

A radiology instructor of mine often joked that anytime cats experience health problems, they do one of three things (or all of them): they vomit, stop eating their food, and pee outside the litterbox.

 

This is some tongue-in-cheek humor, but true in many cases for kitties. This does mean there can be many reasons why a cat decides to pee outside of the box including both medical and behavioral causes, but the first thing we rule out at the vet clinic is a primary medical urinary tract issue.

 

If a cat is experiencing urinary tract discomfort, she may identify the litter box with that source of discomfort, opting to pee somewhere else. It’s also thought that when the urinary tract is uncomfortable, many cats find urinating on smooth, cool surfaces, like a tile floor (or bathtub like my cat) to be soothing.

 

When Pee’s Not Yellow

If your cat’s urine ever takes on a dark brown or red color, there is likely blood present, which should never normally be present in urine. 

 

Now, to clarify, cat urine is often more concentrated normally and so should typically always be a darker yellow. 

 

But brown or red is the sign of a problem, with the urinary tract itself being the primary concern. 

 

I’m Not Peeing at All

If you’re not finding any urine clumps in the box this should raise your level of concern that something is wrong, but there are two ways this might present. 

 

If you’re not finding urine clumps in the box but you have observed your cat attempting to use the box multiple times, this could be the sign of a urinary blockage, which as we’ll discuss more later, is considered a medical emergency requiring immediate care.

 

If you’re not seeing urine clumps but you’re also not seeing your cat using the box or aren’t sure, it is possible that he’s urinating somewhere else. Kitties that venture outdoors often find places to urinate outside. 

 

If your cat is indoor only, it can be worth spending a few minutes looking around the house, especially dark places like closets, bathrooms, piles of clothing, and behind furniture.

 

If you’re not able to find anything with a quick but thorough search, it’s better safe than sorry to have your vet check your kitty out and make sure a urinary obstruction is not present.

 

Cat With Possible Urinary Infection

The Two Main Categories of Urinary Tract Disease

While there can be many causes of cats peeing more or peeing in inappropriate places, when we’re talking about actual urinary tract disease, there are two broad classifications: urinary tract infections in cats (UTIs) and what we term feline lower urinary tract disease (FLUTD)

 

The UTI

Our first major category is the urinary tract infection. This is the classic condition that most pet parents think of if they see their kitty urinating outside of the box, having an urgent need to go, or seeing blood in the urine.

 

Urinary tract infections are caused by bacteria that work their way up the urinary tract and set up shop in the bladder. The bacteria that cause UTIs are typically introduced either from the skin surrounding the outer urinary tract, or from the environment.

 

Cats are very fastidious groomers. But sometimes grooming behavior can introduce bacteria to the urinary tract, especially if a cat is trying to clean up after a bowel movement or remove some stuck litter.

 

UTI’s are seen far more often in female cats because their urinary tract is shorter, more open, and positioned more closely to the anus, making cross contamination of the urinary tract more likely to occur.

 

Male cats do sometimes get true UTI’s, but less commonly. They more often develop feline lower urinary tract disease, which is our second category we’ll get to in a minute.

 

Many UTI’s are caused by Staph bacteria, normally found on the skin, and the urine itself will not appear much different, but we will see changes in urinary patterns like increased urgency and litter box usage. 

 

But certain bacteria, like E. coli, found in fecal material or outdoor environments, contain toxins that cause tissue inflammation, leading to thickening and irritation of the bladder wall, resulting in the blood that we sometimes see in the urine.

 

When you bring your kitty to the vet, the first place we all start is with a urine sample. In cats, since we can’t just take them out to pee, it’s very common to collect a sample using a needle and syringe inserted into the bladder, often using ultrasound imaging for guidance. This is very safe in the hands of an experienced doctor or nurse. The bladder easily seals itself after the small needle is withdrawn.

 

Collecting a sterile sample in this way is very important. A sample collected from a surface the cat has peed on can be easily contaminated with bacteria, creating the illusion that a UTI is present, when really another cause is responsible for the urinary signs.

 

In a urine sample, we look for signs of inflammatory cells, blood, and bacteria. If evidence supports a UTI, an antibiotic course, typically for 10-14 days, is normally prescribed.

 

Now, it does sometimes happen that when a cat is peeing so frequently from the urgency created by a UTI, the bladder is completely empty and a sample can’t be collected. In these cases, your vet may either have your cat stay for a couple of hours at the clinic to collect a sample later, or may choose to treat empirically with antibiotics based on the signs and behavior seen at home. 

 

Most urinary tract infections in cats clear up with the first course of antibiotics, with improvement noted in just a day or two. Resistant and recurrent UTI’s in cats tend to be uncommon. But if a true UTI is persistent, your vet may recommend culturing a sample of urine to find out specifically what type of bacteria is responsible and what antibiotic it will respond to.

 

The best way to prevent a UTI in your kitty is to keep the litter box environment as clean as possible. Cleaning at least every day is best. Many cats, especially the ladies, squat very low to pee. If the litter is not clean, it presents a risk of bacteria or fecal material reaching the urinary tract, especially when your kitty grooms afterwards.

 

Cats who are overweight or obese can have a great deal of difficulty grooming their hindquarters. Matted hair, stuck litter or adhered fecal material can lead to bacterial overgrowth in unsanitary areas leading to skin infections and development of UTI’s. 

 

If your cat is overweight, it’s important to discuss this with your vet and develop a plan to get her to a more ideal body weight. In the meantime, regular sanitary trims of the hindquarters with your vet or groomer can keep that area cleaner and at less risk of a flare-up.

 

If your cat has increased risk for UTI’s, either due to being overweight, having a less robust immune system, or other identified causes, trying a cranberry supplement, like Cranberry Plus with Echinacea may be beneficial.

 

The principle behind cranberry supplements is that their main active component, proanthocyanidins, can prevent attachment of bacteria, and more specifically E. coli bacteria, to the bladder wall. In theory, if bacteria can’t attach to the bladder wall, colonies can’t be formed and an infection can’t proliferate. 

 

There is conflicting evidence in both the human and pet fields for how effective it truly is. But anecdotally, there are many who feel a cranberry-based urinary tract supplement does help reduce the risk, and when used in small amounts, can be considered safe to use.

 

Conflicting evidence may be because there can be many causes of urinary tract signs in cats and not all are urinary tract infections. You’ll see what I mean when we get into our second category of urinary tract disease.

 

Cat With UTI 3

 

FLUTD: To Pee or Not to Pee

Feline Lower Urinary Tract Disease (FLUTD) is also sometimes referred to as just Lower Urinary Tract Signs (LUTS), or Feline Urologic Syndrome (FUS).

 

These terms refer to a collection of non-infectious urinary tract disorders that can appear very similar to a UTI. 

 

It is far more common to see FLUTD signs in male cats with true UTI’s comparably rare in males. And while female cats can certainly develop signs of FLUTD too, UTI’s are typically more common for the ladies.

 

There are three main categories of FLUTD in cats: Feline Idiopathic Cystitis (FIC), Bladder Stones, and Urinary Obstruction. We’ll go through each one next.

 

Feline Idiopathic Cystitis

FIC is the most common FLUTD condition seen. Idiopathic is a term used to describe a condition without a specifically known underlying cause. FIC is a condition that consists of the bladder wall getting thickened and inflamed. This leads to bladder discomfort and associated signs of blood in the urine, urgency and straining to pee, frequent pees with very little urine output, and urination in inappropriate places.

 

As the name suggests, the specific cause for a cat developing an FIC episode is not completely understood, and requires first ruling out other causes of similar signs, including UTI’s and bladder stones. 

 

It is thought that an underlying stress the cat is experiencing somehow manifests into bladder inflammation, leading to the condition. 

 

What kinds of things stress out cats? There can be many, but the most common include environmental changes like moving to a new house or getting new furniture, changes in food or feeding schedule, and changes in the household like new pets or a new baby. 

 

In my own experience, I have also seen overweight and obese cats develop these signs more often, suggesting that the state of chronic inflammation that excessive body fat causes may also play a role in stress on the body.

 

Treatment most often consists of ruling out other causes of similar urinary signs, like bladder stones and UTI’s, and then treating empirically with a pain medication. Interestingly, anti-inflammatories like steroids and non-steroidal anti-inflammatory drugs (NSAIDs), seem to have little effect on the condition and are not often prescribed.

 

Your vet may also prescribe a medication called prazosin, which can help to relax the urinary tract and reduce straining, bringing signs of relief. 

 

The most important thing for both treatment and prevention of FIC is targeting stressors if they are known, and reducing them in the home. 

 

Making sure there is at least one more litterbox than the number of cats in the home is an important rule to follow. Cats often like to have a couple of choices of where to do their business. All litter boxes should be in low-traffic areas and in places that are darker and more quiet if possible. 

 

Environmental enrichment is important. Indoor cats should have perches or towers where they can see outside. Interactive toys, even just simple ones that encourage predatory and hunting behavior, have shown to be beneficial.

 

One trick to encourage hunting behavior and to give your kitty a “mission” to follow everyday is to hide small amounts of his daily allotment of food in different places around the house each day. This encourages him to “hunt” and seek out his food, providing both mental and instinctual stimulation, as well as some extra activity. 

 

There are some products designed just for this purpose that you can hide small amounts of food in, like Doc and Pheobe’s Indoor Hunting Cat Feeder, which was developed by a veterinarian.

 

Every cat should have at least 15 minutes of play activity per day. If your kitty is not the super active type, encourage some 5 minute play sessions a couple times during the day with toys, a laser pointer, etc.

 

What about letting your indoor cat outside? While it's true that experienced indoor/outdoor cats do appear to show signs of FIC less commonly, I don’t advocate suddenly letting your indoor-only kitty out to roam around outdoors in the hopes it might prevent episodes. 

 

I have still seen indoor-outdoor cats develop FIC, and there are certainly some significant risks and stressors outdoors for them to worry about. A cat not used to outdoor noises and environments is more likely to be terrified than relaxed, leading to panic and possible injury.

 

If your kitty goes outside, it can also be harder to monitor urine output and may delay detecting any important changes.

 

Getting your cat used to walking on a harness leash is a reasonable happy medium you can try.  Not all cats will do well with it and it can take some getting used to, but a stroll around the house with you to sniff at the garden and peer at birds and other interesting things can be enriching for a kitty well-acclimated to a leash.

 

Bladder Stones

Bladder stones are mineral-rich concretions that form in the urinary tract. At the least they cause bladder irritation, inflammation, and our typical urinary signs. At the worst, they can cause life-threatening obstructions in the urinary bladder or urethra. This is especially true for male cats, who have longer, more narrow urethras.

 

There are two main types of stones that can form. Struvite stones are composed of magnesium, phosphorus, and ammonia. Oxalate stones are composed of calcium. 

 

The types of stones that form can depend a lot on urine pH and diet, but likely also on individual traits of the cat himself. Remember my short story about my own cat urinating in the bathtub? Well, Teach ended up having a couple of bladder stones. Of my three cats who are all littermates and who were all on the same diet, only Teach ever developed stones. 

 

Bladder stones can be diagnosed at the vet using either x-rays or ultrasound. Because it’s common nowadays to use an ultrasound to guide collection of a sterile urine sample from the bladder, diagnosis with ultrasound is more convenient and more common if the vet practice has one. 

 

While these diagnostics can diagnose the presence of stones, they cannot tell which type is present. You can only do that by sending the stone itself out to a special lab to have it tested.

 

There are a couple of ways bladder stones are addressed. Struvite stones can be dissolved with a prescription diet, though this is a slow process, often taking a few weeks if there are large stones or multiple stones present. 

 

Calcium oxalate stones cannot be dissolved by a diet and have to be removed. For small stones that are few in number, it can be possible, with a cat under heavy sedation or anesthesia, to flush the bladder with sterile saline, dilating the urethra enough for the stones to pass. Fortunately for my cat Teach, his stones were small and were cleared out using this method.

 

Because you can’t tell what type of stone is there and waiting for stones to dissolve over a few weeks presents a risk for urinary obstruction especially in male cats, it’s common for surgical removal of the stones to be recommended. 

 

However the stones are removed, it is common for them to come back without proper prevention. The only method to reliably prevent the formation of either struvite or calcium oxalate stones is with a prescription diet.

 

Prescription diets prevent stone formation by keeping the urine pH exactly in the middle, avoiding high pH favored by struvite stones, or low pH favored by calcium oxalate stones. They also are low in oxalates and magnesium which are required for formation of stones. 

 

Once a cat is on one of these diets, he has to stay on it for life, or risk the return of the stones. The good news is that these diets are well-balanced and formulated for complete nutrition, meaning that other cats in the household can eat them as well. I have had all three of my cats on a prescription diet for several years and have not had any recurrence. 

 

Urinary Obstruction

Urinary obstruction is the most dangerous and life-threatening urinary tract condition we see in cats. The term “blocked cat” typically refers to this condition. While female cats can in theory be affected, the scale tips very far in favor of male cats getting blocked because of how long and narrow their urethra is.

 

Urinary obstruction can be caused by small bladder stones lodging themselves in the urethra. But we can also see obstructions caused by things called mucus plugs, which are a collection of mucus-like protein, cells, and sandy mineral grit. 

 

I have also on rare occasion encountered a male cat with a bladder so inflamed from presumptive FIC that the urethra is swollen near the neck of the bladder, leading to obstruction.

 

A urinary obstruction in a cat is always an immediate emergency. If urine cannot be passed, the kidneys cannot continue to filter out waste products and certain electrolytes, like potassium, from the bloodstream. These waste products will build-up in the bloodstream, causing progressively severe illness and eventually death. 

 

It is also possible for a blocked bladder to fill and become distended enough that it ruptures, spilling urine into the abdomen, which typically results in a fast developing peritonitis and death.

 

Blocked cats can decompensate very quickly, with death occurring in just 24-48 hours. This means that severe disease can develop sooner than that. 

 

A blocked cat will often start by showing a sense of urgency to pee by either going back and forth to the box multiple times, or by straining in multiple places throughout the house. The hallmark though, is that no urine is produced. 

 

Generally, if you notice that your cat is making repeated trips to the box (sometimes several in the course of an hour) but there are no new urine clumps during a one hour period, there is sufficient concern to take him immediately to a vet for evaluation.

 

Cats that have been blocked for longer will often have a poor appetite, develop lethargy, and may start to vomit from the waste products building up in the bloodstream.

 

A blocked cat is treated as an emergency at any vet hospital, always taking priority. Referral to an emergency center is common. 

 

The first thing we do is work on unblocking the kitty. This consists of anesthesia to relax the cat and relieve straining behavior so that a urinary catheter can be inserted into the urethra to relieve the blockage.

 

The bladder is then often flushed generously to remove sandy mineral grit, blood clots, and other material. Labwork is typically performed to determine if kidney waste product values like BUN and creatinine and electrolytes like potassium, have increased to concerning levels.

 

Blocked cats are then often hospitalized on intravenous fluids on average for 2-3 days with an indwelling urinary catheter. This is to flush out waste products, continue to flush out the bladder of debris, and to counter the body’s reflexive diuresis in response to unblocking. Post-obstructive diuresis as it’s called, is an excessive ramp-up in urine production by the body. It can lead to severe dehydration after unblocking when the body overcompensates when a urinary blockage is relieved. 

 

A urinary catheter is then typically removed after about 48 hours and the cat’s urine output and behavior is then monitored for another day. If he does well through day 3, he’ll typically go home. If however, he re-obstructs without the catheter, the catheter then has to be replaced and the process repeated. 

 

Blocked cats generally have a good survival rate if brought into a vet hospital promptly enough. However, the risk for re-obstruction for cats can be frustrating with the percentage of cats reblocking being roughly 20%-50%, often within the first week after treatment or discharge from the hospital. 

 

This then gets us to a surgical procedure that can be performed in male cats with a high risk of reblocking, called a perineal urethrostomy. 

 

This procedure involves surgically opening up the urethra just below the anus, similar to where a female cat’s urethra exits. This makes the urethra shorter and more straight, making it easier for any sediment or material in the urine to pass, and preventing blockages from occurring.

 

Perineal urethrostomy is often first discussed if a cat re-blocks within 1 week to a month after the first urinary obstruction episode. The procedure can have a very high rate of success preventing future blocking episodes, but it can increase the risk for urinary tract infections and will not prevent the underlying cause of blockage (like FIC, diet, etc.), so urinary behavior still needs to be closely monitored.

 

Because urinary obstruction is typically associated with the causes of FLUTD we’ve already discussed, like bladder stones and underlying stressors, prevention methods are essentially the same. Cats at risk for FIC and stone formation should be on prescription diets and all of the environmental enrichment factors discussed under FIC should be followed.

 

Cat With UTI 2

Keeping Things “Pee-ceful”

If your kitty starts showing signs of urinary abnormalities, it can be both concerning and frustrating to deal with, greatly affecting the special bond you share with your furry friend.

 

At the start of a problem, make sure to have your feline friend fully evaluated at your vet. It’s important to rule out urinary tract infections as well as conditions like bladder stones or FIC before assuming the cause is “just” behavioral. 

 

If a behavioral cause is suspected, your vet can recommend natural calming pheromone products like Feliway. If underlying stressors cannot be targeted and removed, medications focused at reducing stress and anxiety may also be beneficial. 

Topics: Cats, Pet Health