Do you know the signs of a cat urinary blockage? Do you know about FLUTD? Maybe you’re puzzled why your cat suddenly pees outside the box? Or maybe he strains and strains but can’t eliminate. Is it constipation? Or does he have a cat urinary blockage? How can I stop my cat from peeing on the carpet?
If you’re asking these questions, you’ve come to the right place. Feline lower urinary tract disorders (FLUTD) can cause deadly cat urinary blockage. It frustrates cat owners—and also the cats! A cat urinary blockage can be deadly, so it’s vital to recognize the signs of a feline urinary tract disorder. This post is dedicated to my friend Susan Richardson-Cripps and the memory of Heathcliff, a fun-loving orange boy.

Cat Urinary Blockage & Disorders
Your cat has always been faithful to the litter box. After all, you trained your kitten to use the litter box from the beginning. But suddenly your adult cat, Tom, leaves damp messages on the carpet, Sheba cries and squats right in front of you, and bloody urine puddles in the bathtub. This is different from urine spraying, and is a cry for help.
My dear friend Susan messaged me on a Friday evening, concerned her cat Heathcliff had constipation. Although he managed to defecate, he still seemed to have a lot of pain. He walked “funny” and meowed a lot. She’d called her vet but couldn’t get an appointment until Monday afternoon. I suggested the local emergency hospital, and the next morning, she took her orange boy there for an exam.
Some litter box problems can be easily solved with these tips. When your well-trained cat suddenly begins missing the mark, that can be a sign of a health problem. Any health issue requires veterinary help.



Cats with urinary tract disorders often spend lots of time just sitting in the box.
Feline Lower Urinary Tract Disorders (FLUTD)
Cats are known to suffer from a group of disorders, including stones, as a part of Feline Lower Urinary Tract Disease or FLUTD. Male and female cats are affected equally. Urinary bladder stones occur in only about 20 percent of cats suffering from LUTD.
Actual “stones” of pebble-size and larger can develop. More commonly the tiny mineral deposits (called urolithiasis) are microscopic to sand-size. A mucous-crystal matrix can plug the urethra and prevent the bladder from emptying and cause cat urinary blockage. Just think back to your childhood, remember a never-ending car trip with no bathroom access. Multiply that discomfort tenfold to understand how the blocked cat feels.
Signs of Cat Urinary Blockage
Signs of urinary stones may include any one or combination of a break in housetraining, dribbling urine, straining in the litter box or spending lots of time “posing” with little result–this can look like constipation. When urine does pass it may contain blood, and/or have a strong ammonia smell. Affected cats may cry during urination, or excessively licking the genitals.
Diagnosis is based on these symptoms, urinalysis, and/or X-rays to reveal stones in the urinary tract. Without prompt medical attention, the blocked cat will die when toxins build up in the bloodstream, the kidneys stop working, or the bladder ruptures.



I love Heathcliff’s single freckle on his nose! He apparently loved to hunt and fetch snakes into the house, yikes!
Heathcliff’s Sad Experience
The veterinary emergency clinic examined Heathcliff and explained to Susan that his bladder had enlarged to softball size, filled with bloody urine and crystals. They anesthetized him to place a urinary catheter to help him pass the urine, and planned to prescribe pain medication and antibiotics to address possible infection. Tragically, five-year-old Heathcliff’s heart stopped after he came out of anesthesia, and didn’t survive despite attempts to save him.
“Our sweet boy was only five years old. How does this happen so fast to a beautiful and energetic cat? He went downhill so fast.” She hadn’t seen any bloody urine at all until at the clinic, and Heathcliff had acted like his normal, rambunctious self only a few hours earlier. “They did all they could to revive him, but our little guy just didn’t have the fight in him. I do want to say thank you to Christian and the staff at Grayson County Animal Emergency Clinic for the kindness they showed me and the gentleness they showed to Heathcliff.”
FLUTD & Creating Kitty Urinary Crystals
Not all stones are the same. Crystals and/or stones form when specific minerals and organic substances are present in the urine in the right concentrations. In addition, the urine must be the right pH (acid/base balance). It also must stay in the bladder long enough for crystals to form. Consider pancake syrup in a pan–if it sits still long enough, crystals form. Therefore, formation of stones depends on volume of urine, concentration and type of minerals, frequency of urination, and genetics.
Cats evolved as desert creatures, and consequently conserve water extremely well. They may urinate only once every 24 to 48 hours. That means urine sits in the bladder for long periods and becomes more and more concentrated. Cats also drink sparingly, and seem to prefer to get water from their diet rather than lapping from a bowl. These instinctive tendencies predispose felines to develop bladder stones. Some kinds of crystals like struvite can be managed easily with diet. Others like calcium oxalate stones are a challenge–and diets that prevent one actually promote the other kind. Yikes!
The cause of feline crystals often can’t be identified. Diet can play a role in the formation of certain types of feline stones. And because up to 70 percent of cats have repeated episodes of stones, a therapeutic diet has become the standard way to treat and in some cases prevent them.
Cat Urinary Crystals
Twenty-plus years ago, 80 percent of feline bladder stones identified as struvite and developed in part due to alkaline urine. Pet food manufacturers learned to counter this by creating acidic urine (and therefore prevent struvite formation) by adjusting the formulation of cat diets. Bless their furry lil’ hearts! Nearly every commercial cat food on the market today has been designed to reduce the chance of struvite formation, by increasing the acidity of the urine.
When the diet has undergone expensive tests to prove this effect, the label may say, “for urinary tract health.” Honestly, though, all of the major cat food brands do pretty much the same thing. They just haven’t spent extra money on these tests and so legally can’t place a claim on the label.
A percentage of cats still develop struvite stones despite eating good foods. Special therapeutic veterinary diets can dissolve existing stones and/or prevent formation of new ones, and most of the major pet food manufacturers offer therapeutic options. Therefore, if your cat hates the first food offered, ask about another therapeutic alternative. Diets only work if the cat eats them.
Cats that become blocked from urethral plugs–crystals mixed with mucus that get stuck in the urinary track–typically are unblocked with catheters to reestablish flow from the bladder. But repeated catheter use may cause scar tissue in the urethra that makes the problem even worse. Perianal urethrostomy surgery may be an option for these cats. The procedure shortens the male cat’s urethra—removes the penis—which creates a wider conduit for release of urine so the urethra doesn’t block as easily even if crystals continue to form.
More Urinary Crystals & Calcium Oxalate Conundrum
The change in commercial diets to reduce struvite actually promoted a rise in calcium oxalate stones. These struvite-prevention diets increase blood-acid levels, which also tend to leech calcium from the bones. Calcium spilled into the urine can form calcium oxalate stones. Calcium oxalate stones most typically block the ureters–the conduits leading from the kidneys to the bladder–and if too big to pass, require surgery to remove.
FLUTD & Stopping the Stones
So, what can a cat lover do? Be alert for signs of distress. Consider a blocked cat a life-threatening emergency and see your veterinarian immediately. Do your best to reduce cat stress, since that can predispose kitties to repeated episodes.
If your cat has been diagnosed with FLUTD, your doctor likely will analyze the crystals (if present); determine if an infection is involved and prescribe medication and recommend an appropriate diet. Remember that an old cat with calcium oxalate crystals should NOT eat a food designed to prevent struvite, or vice versa. In addition to diet change, avoid giving any kind of mineral or vitamin C and D supplementation to cats, which can predispose to calcium oxalate formation. The veterinarian has the information to prescribe and recommend the most appropriate treatment for your individual cat.



Heathcliff (in the chair) with best kitty buddy Monty.
Dilute With Water
Increase your cat’s water intake by feeding canned diets, which typically feature 70 percent water. There’s some argument whether or not cats drink more when the water remains fresh or running. It won’t hurt to provide a feline drinking fountain, available from pet products stores. More water helps dilute the urine and encourages the cat to use the litter box more often. That way the bladder doesn’t remain full for long periods of time.
While filtered or bottled water isn’t routinely recommended, it probably won’t hurt and might help especially if it encourages your cats to drink more. Try flavoring the water with liquid drained from water-packed tuna or a bit of no-salt chicken broth. All’s fair in keeping cats healthy–sometimes despite themselves.
Susan gave me permission to share Heathcliff’s story, in the hopes it might warn other cat lovers and save them the pain her family feels. “Monty misses his baby brother, Heathcliff. He has wandered all over the house today looking for him and can’t understand where his wrestling buddy has gone. I’m afraid Monty is going to find this difficult to deal with because they were inseparable.” I’ve written about helping yourself, and pets, through the grieving process.
Karma-Kat has always remarkably healthy and (knock wood!). He never misses the litter box and this tragic story reminds us all how quickly a vibrant, health pet can suffer a life-threatening health crises. We’re fortunate to have a veterinary ER available in our community. What about your cats? Have they had problems missing the box? Crystal issues? What has been your kitty experience with regard to lower urinary tract issues?
I love hearing from you, so please share comments and questions. Do you have an ASK AMY question you’d like answered? Do you have a new kitten and need answers? Stay up to date on all the latest just subscribe the blog, “like” me on Facebook, and sign up for Pet Peeves newsletter. Stay up to date with the latest book giveaways and appearances related to my September Day pet-centric THRILLERS WITH BITE!
Amy Shojai, CABC is a certified cat & dog behavior consultant, a consultant to the pet industry, and the award-winning author of 35+ pet-centric books and Thrillers with Bite! Oh, and she loves bling!
My 4 year old boy had a urinary blockage 6 weeks ago. They visually saw mucous when he was catheterized. He was put on prescription dry and wet food. I give him 1/4 cup of dry because he never eats all of the wet. He consumes about 1/3 of a 5
5 oz. can 2x a day. He is 12lbs. I feel like he needs more and I never see him drink from any of his fountains. I would like to give him a topper to entice more wet food eating but I am confused about what I can add to his diet. Maybe a non prescription urinary tract wet food of a different flavor mixed with the prescription wet food? Is bone broth safe? what are your thoughts?
Hi Kelly, I’m so glad you got your boy help! Yes, it can challenge us to get cats to eat the therapeutic foods that help them. I’d urge you to ask your vet for ideas for a topper that won’t distrupt the benefit of the food. In particular ask about Churu, these tend to prove irresistible to cats and might help entice your kitty to eat more.
Hi Amy,
I am familiar with this, as I have had cats most of my life. I had one cat, Cocoa, who told me he was having problems. He would sit over the drain in the bathtub and cry and cry. I took him to the vets and he had surgery to remove the stones/blockage. He felt great for a month or so and started crying in the bathtub again. So back to the vets we go. He had a second surgery. A few months later, I couldn’t believe that the poor baby was having problems again. So, back to the vets we go. Unfortunately, the vet told me that he wouldn’t survive another surgery or if by some miracle he did, this would keep happening. Once they get these stones/blockages they are more prone to having them again. Not saying they will get them but they are more prone. So, I had to make the decision of having to put him to sleep or having him chance the surgery. I made what I thought was the most humane thing to do for him and had him euthanized. When we got another cat, a different vet (our 24 hour ER/veterinarian hospital is also a teaching hospital) told us to make sure that we only feed, the cat, a low ash diet.
I don’t know if the labels say low ash anymore as my 2 house cats are on a special diet for indoor cats. Plus, I do filter any drinking water as the chemicals are too strong in our water. If I am not going to drink it, I am not going to give it to my animals.
Something to look into if your cat is prone to developing stones, and that is Chanca piedra aka: Stone Crusher, which helps to dissolve and break up the stones (I take it when the need arises because I develop gall stones) and D-mannose to help sooth their bladder. They do give Chanca piedra to pets as well as humans. I give it to my boy on occasion when I think he is in need. I mix about 1/8 tsp (about the amount of a capsule which is how it comes if you search online for it for pets) into a dab of sour cream. Your cat will let you know when they don’t need it any more, at least mine did. He refuses to eat it when he feels better.
Thanks for sharing. The tea (Chanca piedra) may indeed help with human kidney stones. The type of stone matters, though, so I’d always run such things past the veterinarian first since there are different types of stones in cats (some of mixed composition). And I’m not well versed in human medicine enough to know if people gallstones and kidney stones match those of cats (or dogs). I’m always interested in learning new approaches!
Thank you for this. I’ve been through this problem with one of my cats…really scary.