Your cat has always been faithful to the litter box. But suddenly Tom leaves damp messages on the carpet, Sheba cries and squats right in front of you, and bloody urine puddles in the bathtub.
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 but 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. 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 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, bloody urine or urine with a strong ammonia smell, crying 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.
Creating Kitty 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), and 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, which 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, while 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, diet has become the standard way to treat and in some cases prevent them.
The Struvite Solution
A dozen years ago, 80 percent of feline bladder stones were struvite and developed in part due to alkaline urine. Pet food manufacturers discovered they could counter this and create 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 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.
Calcium Oxalate Conundrum
Today calcium oxalate stones are becoming most common. Struvite seems to affect younger cats while calcium oxalate more often impacts aging felines. In fact, some calcium oxalate uroliths, especially those in the kidneys, may not cause obvious health problems for months to years. As the cat ages, the bladder becomes less elastic and may not empty totally each time the cat urinates. Over time, this may lead to increased susceptibility to infections and large bladder or kidney stones.
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. When this calcium is spilled into the urine it 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.
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 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.
Increase your cat’s water intake by feeding canned diets, which typically feature 70 percent water. Cats seem to drink more when the water remains fresh or running, so 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, so 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.
Seren has been remarkably healthy and (knock wood!) hasn’t had problems with hit or miss litter box issues. 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?
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