Common Feline Health Problems and Their Ties to Diet: Urinary Problems

Urinary Tract Problems include Cystitis (bladder inflammation), Urethral Blockage, Bladder/Kidney Stones.

Read more about Feline Urinary Tract Health HERE.

Cystitis can lead to inappropriate urination (urinating outside of the litter box) and 
stones can cause a fatal rupture of the bladder by blocking the outflow of urine.

Any cat that is repeatedly entering the litter box but not voiding any urine is in need of IMMEDIATE medical attention!  

This is one reason why it is so important to use a clumping (scoopable) litter.  

Clumping litter allows you to see just how much, if any, urine is being voided.

It is important to note, however, that “crystals” are not the same thing as stones.  

Crystals are often a normal finding in a cat’s urine and it is not necessarily appropriate to put the cat on a “special urinary tract” formula when these are found in the urine.

Important: I often see too much clinical significance placed on the identification of crystals in the urine without regard to how the urine sample was handled.  

It is very important to understand that crystals will often form once outside of the body within a very short (30-60 minutes) period of time.

If the veterinarian does not examine the urine right away and either sends it to an outside laboratory or uses a free-catch sample that the owner brought from home, an erroneous diagnosis of crystals may be made.  

This is called a “false positive” report and results in unnecessary worry on the part of the owner and often leads to the cat being placed on an inappropriate, low quality diet.

With regard to overall kidney and bladder health, I cannot stress strongly enough how important water is in both the prevention and treatment of diseases involving this organ system.

When a cat is on a diet of water-depleted dry food, they produce a more highly concentrated urine (higher urine specific gravity – USG) and they produce a lower volume of urine (often half of what a cat on canned food produces) which means that a higher concentration of crystals will be present in the urine.

This increases the chance of these crystals forming life-threatening stones.  It is also thought that the highly concentrated urine may be very irritating to the bladder wall in some cats, predisposing them to painful cystitis.

Please keep in mind that a cat has a very low thirst drive and is designed to get water with their food.  

A diet of canned food will keep a proper amount of water flowing through the urinary tract system and help maintain its health.

Adding 1-2 tablespoons of water (plain or flavored – such as tuna water, clam juice, chicken or beef broth) per meal is also very beneficial.  Make your own tuna water by taking one can of tuna and mixing the contents into 3 cups of water.  Mash it up and let it sit for ~15 minutes.  Pour the water into covered ice cube trays.  Freeze to prolong the freshness.  Use covered trays to keep the water tasting and smelling fresh.

Water fountains may also help cats consume more water but feeding a water-rich diet is much more effective in increasing your cat’s water intake than water fountains or multiple bowls of water sitting around your house.

Urine pH is also often considered when discussing urinary tract problems but we really need to stop focusing so heavily on pH. Again, a proper amount of water in the diet is the important issue here – not urine pH.

Many of the often-prescribed feline lower urinary tract diets are formulated to make the urine acidic but it is thought that these low magnesium, acidifying diets may actually exacerbate painful cystitis. Also, these acidifying diets often end up promoting calcium oxylate stone formation and can also lead to hypokalemia (low potassium in the blood) which can cause or exacerbate kidney disease.

It is also important to note – for those people still stuck on worrying about the urine pH – that there are many factors which determine the pH of urine and only one of them is diet.

Urine pH varies throughout the day and using one pH measurement from a single urine sample is very misleading and is not terribly helpful information.

With regard to dry food and urinary tract health, aside from the lack of water in this type of diet, there is also a correlation between the consumption of a high carbohydrate diet and the formation of struvite crystals as shown by this study because carbohydrate diets promote an alkaline urine.

Veterinarians often prescribe Hill’s Prescription dry c/d for urinary tract problems but again, these diets are only ten percent water and contain a high level of species-inappropriate ingredients and questionable preservatives.  They are also very high in carbohydrates with dry c/d containing 42 percent of its dry weight as carbohydrates.

Please note the first few ingredients in c/d while remembering that your cat is a carnivore:

Previous formulation:

Brewers rice, 

chicken by-product meal, 

corn gluten meal, 

pork fat (preserved with mixed tocopherols and citric acid),

chicken liver flavor, 

taurine, preserved with BHT and BHA

Newer formulation:

Brewers rice, 

corn gluten meal, 

chicken by-product meal, 

pork fat (preserved with mixed tocopherols and citric acid), 

chicken, chicken liver flavor, 

fish oil,

Note that Hill’s removed the BHA and BHT but are now using more corn gluten meal and less chicken by-product meal.

Diet is not the only issue involved with cystitis but it is an important one and one that we can control.  Stress is also thought to play a very significant role in cystitis and even cats that are fed a 100 percent canned food diet may experience bouts of cystitis.

This is a very frustrating disease to deal with and one that the veterinary community does not have all the answers for.  What we do know is that decreasing stress and increasing the water content of the diet are the most important management issues to address.  The water content of the diet is easy to control – feed canned food with added water.  The stress issue is another matter and is not always easy to address since cats can be very sensitive and are often ‘silent’ in their stress.

Cystitis can be extremely painful and it is very important to address pain management in these cats.  Remember:  pain = stress and we are trying to minimize the stress in these patients.

Buprenex is a good choice for a pain medication and I often dispense it for the client to have on hand for chronic cystitis patients – as long as the client understand the critical importance of close monitoring of the patient to make sure he is passing urine and is not obstructed.  (I say “he” because males have a long, narrow urethra and are much more apt to block than females but females can also experience an obstructed urethra.)

Buprenex is superior to Torbugesic which has been used for pain management in the cat in the past.  (Burprenex is a prescription medication that you must get from your veterinarian.)

Unfortunately, many veterinarians overlook pain medications as a very important part of the treatment of this common feline problem

A very important note on antibiotic usage in these cases:  Most cases of cystitis are sterile.  In other words, they are not the result of an infection and the patient should not be placed on antibiotics.

Only ~1% of cats with cystitis that are under 10 years of age have a urinary tract infection, yet many veterinarians place these patients on antibiotics when these drugs are not warranted.  Most cats under 10 years of age produce a very concentrated urine (USG greater than 1.035) and bacteria do not grow well in concentrated urine.

In cats over 10 years of age, infections are more common but that still does not mean that older cats with cystitis should automatically be put on antibiotics.  The reason that an older cat is more prone to urinary tract infections is because kidney disease is more common in this age group and so these cats will have a more dilute urine which is not as hostile to bacterial growth.

Diabetes and hyperthyroidism are also more common in cats over 10 years of age and both disease render the patient more prone to urinary tract infections.

That said, only ~20% – or less – of all older cats that present with lower urinary tract signs (see Feline Urinary Tract Health – Cystitis) actually have an infection so ~80% of this age group exhibiting these clinical signs do not need to be put on antibiotics.

A urine culture and sensitivity (C & S) should be run to check for an infection, especially if the patient has a low urine specific gravity or is diabetic.  It must be kept in mind that even with a low USG, most cases of cystitis are not due to an infection.  This is why it is important to run a C & S before placing the patient on antibiotics.

Antibiotics are NOT harmless drugs and they need to be used with more critical thought than is currently happening in both human and veterinary medicine.

This is especially true of Convenia.  Please do not allow that drug to be injected into your cat without reading my Convenia webpage first.

A C & S test identifies the bacteria (if present) and tells the veterinarian which antibiotic is appropriate.  The urine for a C & S needs to be obtained by way of cystocentesis which involves using a syringe and needle to obtain urine directly from the bladder.

This is not a painful procedure for the cat and this method is the only way to obtain a sample for accurate information in order to properly treat with antibiotics.  One problem, however, is that a sample may be difficult to obtain without waiting a couple of hours since cats with cystitis urinate frequently and often do not have enough urine in their bladder to get a good sample.

To get around this problem, your veterinarian can give the your cat a dose of subcutaneous (just under the skin) fluids.  The patient is then put into a cage without a litter box.  Within a couple of hours (or less), the bladder is usually full enough to obtain a urine sample via cystocentesis.

We have to stop treating all cases of cystitis with antibiotics without supporting evidence of an infection!

Cystitis will often recur in these patients and this painful health problem can be very frustrating to deal with.  On a good note, most cats will have their clinical signs spontaneously resolve even without any treatment.  In fact, it has often been said, jokingly, that a cat with cystitis will often stop exhibiting clinical signs within seven days with antibiotics and in one week without antibiotics.

Unfortunately, when people don’t understand this issue, antibiotics often get the credit when they had nothing to do with the patient’s improvement. When this happens, the abuse of antibiotics continues.

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