Bladder Stones

Straining to urinate

Cat in Box
Straining to Urinate

Bladder stones or calculi may not be a topic of interest to most pet

owners unless your pet has had illness related to these mineral densities.

However, you may be predisposing your pet to problems depending on the

diet you currently are feeding.

Cats and dogs can have urinary calculi. Early signs of calculi include

frequent urination, straining to urinate, blood in the urine and/or licking

the urethra. Cats spend extra long times in the litter box. In severe cases

no urine is voided. There are six different types based on the mineral

crystal content in the stone. The body forms these different crystals in

relation to specific diseases. Let me discuss each briefly.

One of the most common calculi we see is called Struvite. This is a

combination of magnesium, ammonia and phosphorous. While dogs or cats of

any breed can have these crystal formations we tend to see cats in severe

emergency states more often. Perhaps since the monitoring of cats for urination

is not a highly visible activity cats may be unobserved until they are

howling and can no longer move. Now the pet is in a critical stage and

must be examined and be hospitalized for catheterization, fluid therapy

and treatment of the crystals. Males have more difficulty trying to pass

these stones because of the small opening of the penis. Females can be

in trouble if the stones are larger. Stones beyond sand size need surgical


In young cats we see Struvites. While the exact cause is not known it

is generally accepted that bladder infections and diet cause development

of the calculi. There a several veterinary prescription diets available.

A few store brand diets are available and are creating a increase in another

type of crystal that we rarely saw years ago. As cats age they can develop

oxalate crystals. The easy accessibility of the store brand diets when

fed to middle aged and older cats creates Calcium oxalate crystals. The

bladder is like a chemistry lab and a few reagents (diet ingredients) and

minerals added here and there will alter the kidney and bladder function.

These are serious calculi causing both lower and upper urinary tract disease.

Urate crystals can form from excess Uric Acid in the bloodstream and

in the urine. Many Dalmatians and Bulldogs develop these crystals. In humans

this causes gout because the joints collect crystals, too. We don’t see

this phenomenon. Treatment of concurrent liver disease and specific low

protein diets often with medication will control the disease successfully.

Xanthine crystals can result if the medication is in excess.

Cystine crystals are found in animals that have an amino acid metabolism

defect. Fortunately these are not common. Breeds which may be predisposed

are Newfoundlands, dachshunds and Siamese.

Calcium Phosphate crystals (You guessed it this is beginning to sound

like a chemistry class.) occur with excess calcium and phosphorus in the

bloodstream and urine. Some times breeders feel they will push their pups

to be have a larger skeletal frame if they supplement minerals. This is

a rotten result.

In nearly all instances the calculi can be controlled with specific

diets and sometimes additional medication. Regular tests on the urine will

be helpful to keep current on the disease of the urinary tract. The best

advice is to feed your pet a good quality diet. Cheaper brands tend to

be high in bone meal which is a large source for minerals. The same minerals

can be found in the bladder stones.

Best Veterinarians in Portland. Husband and Wife Team