FLUTD and Urolithiasis in Cats
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FLUTD and Urolithiasis in Cats
Maegan Gossett, Gerri Pritt
CA Nutrition and Care- Dr. Carpino
November 8, 2015
FLUTD and Urolithiasis in Cats
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There are many different types of diseases in companion animal medicine, whether it be
metabolic, auto-immune, or infectious. Each of these different type of diseases have their own
clinical signs, treatment plans, and outcomes for the patients we see. There are multiple
diseases that have relationships with one another; for instance, FLUTD and urolithiasis. Both of
these diseases involve the urogenital tract, have similar treatment options, and have their own
distinct clinical signs. The relationship of FLUTD and urolithiasis in cats can go hand in hand, as
far as, diagnosing, treating, and preventing future episodes.
Feline Lower Urinary Tract Disease (FLUTD) is a compilation of multiple issues occurring
in the bladder and/or urethra, which all exhibit similar clinical signs. The most common
disorders associated with FLUTD are urolithiasis, urethral obstruction, urinary tract infections,
and feline idiopathic cystitis (FIC). Some of the clinical signs one may see with a cat that has
FLUTD would be dysuria, polyuria, oliguria, hematuria, anuria, urinating outside the litter box,
excessive licking of the genital area, depression, lethargy, anorexia, vomiting, etc. FLUTD often
occurs in cats that are middle-aged, overweight, indoor only, and are on a dry food diet. Cats
can be stressed by simple changes in daily life, so anything from a new pet to a new house, our
feline friends can develop FLUTD (Cornell, 2006).
Urethral obstruction is described as it is named, an obstruction in the urethra. The
urethra is the canal that goes from the bladder to outside the body. It is the only way urine is
expelled from the body. Cats can get urethral obstructions from uroliths and urethral plugs.
Uroliths are stones that develop in the bladder, if they become the right size they can become
stuck in the urethra and block any urine that needs to be expelled. Urethral plugs can form
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when inflammatory material, such as cells, mucus, and/or minerals block the urethra. Urethral
plugs often occur in male cats due to the longer and narrower urethra compared to females
(Cornell, 2006). Urethral obstruction is a medical emergency because the urine is unable to be
expelled from the body, therefore the contents, such as electrolytes and waste materials,
should be leaving the body are then “backed up” in the bloodstream causing toxic levels,
azotemia, which in turn will cause death if not immediately corrected. Common clinical signs
associated with urethral obstruction is dysuria, anuria, crying when using the litter box,
anorexia, vomiting, and/or lethargy (Summers, 2014). Electrolyte imbalance can cause heart
failure, therefore, upon physical exam the veterinarian may notice a cardia arrhythmia.
Diagnosing the reason for the urethral plug will determine what treatment to pursue. The
number one priority is to unblock the cat and fluid therapy to correct any blood abnormalities.
When hospitalization is no longer needed, home care is discussed. An important discussion to
have with a client is a diet plan. Choosing the correct food to maintain a healthy pH and mineral
balance in the urine will help decrease the chances of another plug.
Another disease associated with FLUTD is a urinary tract infection (UTI). This occurs
when bacteria enters the bladder from the outside environment and proliferates. Bacteria can
harbor in the bladder or it can travel to the kidneys if severe enough. UTI’s are more common in
canines, but on occasion a cat can get one too. Females are more prone than males because the
urethra is of shorter distance. Also, cats who have diabetes, hold in their urine for long periods
of time, a male cat who had a perineal urethrostomy (PU) surgery, and/or previous non-sterile
catheterization, are more susceptible to UTI’s. Clinical signs of a UTI would be hematuria,
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polyuria, urinating outside the litter box, licking of the genital area, depression, anorexia,
and/or pyrexia. Diagnostic of a urinary tract infection would be to perform a urinalysis (Cat
World, 2015). Urinalysis results would include the presence of white blood cells and bacteria.
Depending which bacteria is found on the urinalysis, the veterinarian will prescribe the
antibiotic necessary to treat the infection. A recheck urinalysis should be performed to confirm
the infection has cleared. If the infection is still present, the veterinarian may want to perform a
urine culture to determine the exact type of bacteria present and prescribe the associated
antibiotic. Dietary requirements could include increasing fresh water intake to help encourage
increased frequency of urination.
Feline idiopathic cystitis (FIC) is a disease associated with FLUTD, it is a nonmalignant
inflammatory condition in the bladder. FIC is deemed idiopathic, meaning there is no known
cause. Veterinarians often diagnose FIC when diagnostics eliminate all other urinary tract
disorders. It is thought it to be viral, behavioral, environmental, dietary, or stress related, but
studies have not confirmed this. Clinical signs include hematuria, polyuria, discomfort in lower
abdominal area, anorexia, etc. Treatment is subjective in nature, but FIC often times resolves
on its own in about a week to 10 days (Summers, 2014). Researchers suggest to keep
consistency in the household to reduce the risk of FIC. There are diets that are manufactured to
specifically focus on urinary health in cats, but there is no evidence of efficacy.
Lastly, urolithiasis can be associated with FLUTD and is defined as a disease condition
marked by the formation of stones in the urinary tract (Dictionary, 2000). In felines, there are
multiple types of minerals that can comprise a urolith; struvite stones are the most common.
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Stones can be located in any part of the urinary tract, most commonly the bladder, and
diagnosing which kind of urolith is key to treatment.
Diagnostics include urinalysis and radiology. Some stones can be seen on radiographs
and others are not as radiopaque. Those that are not seen on radiographs, can only be viewed
by performing a double-contrast cystography of the urinary tract to determine the amount and
size of stones. The stones can be seen on ultrasound, and determine their position in the
urinary tract.
The cause of uroliths is unknown but there is some speculation involving the diet
offered to the cat. The way that the bladder stones form involves two things: having an
increased amount of minerals in the diet, and by having the correct urine pH to allow
formation. Minerals in the diet that assist in struvite stone formation is magnesium. Certain
diets can change the pH of the urine, struvite stones occur in more alkaline urine. If there are
uroliths that have become lodged in the urinary outflow tract, like the urethra, this will cause a
backup of urine into the bladder. With the urine not being able to be excreted, the bladder
continues to expand to the point of bursting or rupturing. Bladder ruptures are life threatening
and can only be fixed with emergency surgery. With these stones in the bladder, they can
cause some serious damage to the lining of the bladder. Damage to this lining can cause
secondary bacterial infections to occur which only complicates the case.
Clinical signs of urolithiasis can vary depending on the severity, and degree of trauma
present. Some cats can be asymptomatic if there is no obstruction to the outflow of urine.
Cats that have an obstruction will often vocalize or cry when they “use the litter box” because
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of the pain. Cats will tend to “use the litter box” more often than normal with no signs of
actually going to the bathroom. Other clinical signs include: hematuria, dysuria, urinating
outside of the litter box, vomiting, straining to urinate, and death.
Not all urolith diagnosis needs an immediate cystotomy, in some cases, medical
management is the only needed treatment. If there are stones in the urethra, if possible, need
to be flushed back into the bladder. This is using a feline urinary catheter, and normal saline
solution to retrograde the stones into the bladder. If a cat diagnosed with urolithiasis can be
medically managed, they will start off on a new diet. This new diet will help to normalize the
pH of the urine and change the mineral amount in the urine for formation. Antibiotics are
prescribed if there is a secondary bacterial infection caused from damage to the bladder wall.
Radiographs are needed every two to four weeks in order to make sure that the stones are
dissolving properly, and to ensure there are no other stone formations as well. Surgical
treatment involves cutting into the bladder and removing the stones themselves, this is only
after medical management has failed or the stones are simply too large and are causing more
trauma. There are multiple complications to cystotomy surgery, like, stricture and increased
bladder infections, so medical management is prioritized if possible.
FLUTD can be caused by multiple issues, including, but not limited to, urolithiasis. It is
thought that a large portion of urinary diseases in cats is in regards to diet. The composition of
feline diets can harm or protect the kidneys and bladder. If a cat suffers from urinary stones,
the change in diet can help decrease the recurrence of the stones. The clinical signs associated
with FLUTD are all very similar so it is important that cat owners visit their veterinarian when
FLUTD and Urolithiasis in Cats
they notice the signs because it could potentially be life threatening. Cats are a difficult species
to understand, but with new technology and research they have become somewhat
understandable.
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FLUTD and Urolithiasis in Cats
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References:
Cat World (2015). Urinary Tract Infections in Cats - Causes, Symptoms & Treatment. Retrieved
from http://www.cat-world.com.au/how-to-recognise-and-stop-feline-urinary-tract-infectionsearly
Cornell University (2006). Urinary Concerns. In Cornell Feline Health Center. Retrieved from
http://www.vet.cornell.edu/FHC/health_information/UrinaryConcerns.cfm
Summers, A. (2014). Disease of the Urinary System. In Common diseases of companion animals
(3rd ed., pp. 213-216). St. Louis, Missouri: Mosby Elsevier.
(2000, November 5). Retrieved November 5, 2015, from
http://dictionary.reference.com/browse/urolithiasis