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Feline Urological Syndrome (FUS)


Feline Urinary Problems


     F.U.S. is an abbreviation for Feline Urological Syndrome.  More than one in 10-15 cats are prone to this problem.  Due to the magnesium, calcium, phosphorus and other dietary components the cat develops BLADDER STONES which can cause urinary tract infections, blockage of the ability to urinate in male cats and expensive hospitalization and other procedures to diagnose and correct the situation.  F.U.S. is also called feline lower urinary tract disease (FTLD).  Many bladder infections in cats, also called urinary tract infections (UTI), may have FLTD/FUS as the underlying cause.

     We carry the specialty Science, Royal Canin, Purina prescription diets and other cat foods which help prevent the FUS problem.  There are only a few diets which are specifically formulated to prevent this problem and not every cat needs to be on these special diets.  Alpo, Special Kitty, 9-Lives, Purina Cat Chow, Friskies and other brands of food DO NOT prevent this problem.


     IF YOU WANT TO HAVE YOUR CAT TESTED FOR THIS PROBLEM, it is a simple test.  You will need to collect some urine.  The easiest way is to place your cat in a room with a litter box loosely draped inside with clear plastic wrap.  After the cat urinates take a syringe and suck up some urine.  You may also use some special plastic beads in the litter box.  We have these plastic beads for sale. If the urine is contaminated with feces then start over until you collect a clean sample.




Feline Urological Syndrome


     With Feline Urological Syndrome (F.U.S.) the cat’s urinary system creates bladder stones. A newer name for this problem is Feline Lower Urinary Tract Diseases (FTLD).  Kidney stones are different from bladder stones. The kidney is in the upper urinary tract for medical classification purposes. Bladder stones occur due to an individual’s predisposition to developing stones.  These stones are also called urinary calculi. The problem is aggravated by nutritional factors.  If a diet is high in calcium, magnesium, oxalate, phosphorus or other minerals and/or there is an infection that creates a less acidic environment the cat can develop FUS.


 It is not the ash in the food which causes FUS, but only a very small part of this mineral component. (Ash is what is left after burning the food in a test procedure).  There are actually eight different types of stones which can affect the urinary system and each is treated with a different diet.


     Sometimes as pet owners we can cause our cat to develop FUS when they are on a diet which prevents bladder stones but then give the cat supplements or treats.  Some cat treats are very high in minerals.  Even though cats do not need vitamin C in their diets, some owners think this does not hurt a cat.  Excessive vitamin C is broken down into oxalate crystals which are a component in some types of bladder stones.  Some diets sold are high in sodium which may help some cats urinate more and lessen the chance of developing stones. Yet in some cats these high salt diets may cause the cat to go into early kidney failure.  The quality diets formulated for preventing bladders stones do not have excess salt.  We recommend the sodium to be about 0.35% and the chloride to be about 0.7% of the dry matter (DM).Greater than 1% sodium is too high.


     Initially we treat the patient for infections because infections create many of these stones.  Bacterial cultures and an analysis of the stones are indicated since there are many types of bladder stones.  After the analysis we change the diet to treat the appropriate type of stone.


  Long term some patients may also respond to the polysulfated glycosaminoglycan injections which work much better to relive the irritation than the oral glucosamine products.  These glucosamine injections may work best long term for the cat with idiopathic FTLD, a medical name for an irritation of the bladder and lower urinary system for an unknown reason.  Some behavioral drugs are also needed as a trial if all of the above is not working and there is still a reoccurrence.  No treats or other foods can be given with the prescription diets or the FUS will occur. Sometimes just one treat can cause a FUS episode!


     If a male cat seems to be constipated, this can be an emergency.  Male cats can have their urinary tube blocked due to FUS. A bladder infection is much more common than constipation.  A “blocked tom” requires general anesthesia for an attempt to place a urinary catheter in the penis to flush and remove the stones in the urethra which are preventing the urine from coming out.  Fluid therapy and kidney/blood tests are also indicated. Time is important here. Delay between blockage and exam extends hospital treatment for the kidney and electrolyte problems.  Female cats usually do not block since their urethra is larger and allows the bladder stones to pass on through. 

     Most of the urinary problems we see in cats are due to urinary tract infections (UTI), diet/stones (FUS), litter aversion and behavioral problems in this reducing order.  Idiopathic feline lower urinary tract disease (FLUTD) and feline interstitial cystitis or feline idiopathic cystitis (FIC) is discussed more in other specific handout(s).


  With approximately 1 in 10 cats predisposed to this problem you can now understand why we recommend a routine urine test in young and also older cats.


The Staff at the Nelson Road Veterinary Clinic