FELINE LOWER URINARY TRACT DISEASE (FLUTD)
Albert S. Townshend, DVM - Eagle Pet Foods
HISTORY:
- FLUTD has been described as far back as 1925.
- There have been many names give to this condition over the years,
most notable Cystitis, Feline Urologic Syndrome (FUS), Feline Interstitial
Cystitis (FIC) and Feline Lower Urinary Tract Disease (FLUTD). All
of which only describe where and what the condition is but give no
clue as to the cause.
INCIDENCE:
- The incidence is defined as the annual rate of appearance of new
cases of the disease among the entire population of individuals at
risk for the disease.
- For FLUTD the incidence has been reported to be approximately 0.5
to 1.0% per year.
- The above figure should not be confused with the proportional morbidity
ratio of cats with FLUTD. This figure is the frequency with which
these cats are seen in veterinary hospitals.
- For FLUTD the incidence has been reported to be as high as 10%,
but the most common reports are between 1% and 6%.
- These figures would indicate that although the incidence in all
susceptible cats is only approx. 1%, up to 10% of them are seen by
veterinarians and that seems to be a significant number.
- These figures further translates to between 250,000 and 500,000
of the 57 million cats in the United States are afflicted with this
disease annually.
- The condition most commonly affects mature cats and infrequently
immature animals (when it does the cause is most likely to be associated
with bacterial infections).
- Of the 24,000 cat diagnosed with FLUTD in 24 veterinary schools
7% were nonspayed females, 25% were neutered females, 16% were noncastrated
males and 52% were castrated males.
RISK FACTORS:
- Age: Uncommon in cats younger than 1 year of age. Most commonly
occurs in cats between 1 and 10 years of age with peak between 2 and
6 years of age.
- Sex: Urethral obstruction occurs most commonly in males. Nonobstructive
forms
of the disease occur equally in males and females.
- Neutering: There is an increased risk in neutered males and females
regardless of the age when neutered.
- Diet: Consumption of an increased proportion of dry food in the
daily ration is
associated with an increased incidence.
- Water Consumption: Decreased daily water
intake is associated with an increased risk of the disease.
- Sedentary Life Style: Lazy or inactive cats are at increased risk.
- Spring and Winter Season: Some have indicated that there is a seasonal
increase in risk.
- Indoor Lifestyle: Cats using indoor litter boxes for urination and
defecation are at increased risk.
SYMPTOMS:
- Symptoms very generally begin with frequent urination (pollakiuria)
eventually with blood (hematuria). Animal may also display inappropriate
urination (urinating in unusual places). Eventually the cat will typically
become obstructed and unable to urinate (dysuria). The latter almost
exclusively occurs in male cats and is a true emergency.
- Symptoms vary greatly as there are so many causes that have been
identified and so many cases that have unknown causes.
CAUSES:
- The following is a list of known causes of FLUTD taken from "Canine
and Feline nephrology and Urology" by Osborne and Finco 1995.
- Metabolic Disorders (including nutritional)
Uroliths
Urethral Plugs
Inflammatory Disorders
Infectious agents
Viruses (feline Calicivirus sp. and more)
Bacteria (many species)
Mycoplasmas
Fungi (Candida sp. and more)
Parasites (Capillaria feliscati)
Others?
Noninfectious
Immune mediated?
Others?
Trauma
Neurogenic disorders
Reflex dyssynergia
Uretheral spasms
Hypotonic or atonic bladder
Others
Iatrogenic disorders
Reverse flushing solutions
Uretheral catheters (reverse flushing)
Indwelling urethral catheters
Postsurgical urethral catheters
Urethrostomy complications
Anatomic abnormalities
Congenital
Urachal abnormalities
Persistent uterus masculinus
Urethrorectal fistulas
Phimosis
Others
Acquired
Urethral strictures
Others
Neoplastic
Benign
Cystadenoma (bladder)
Fibroma (bladder)
Leiomyoma (bladder)
Papilloma (bladder)
Hemangioma (bladder)
Malignant
Transitional cell carcinoma (bladder and urethra)
Squamous cell carcinoma (bladder)
Adenocarcinoma (bladder)
Unclassified carcinomas (bladder)
Hemangiocarcinomas (bladder)
Lymphosarcoma (primary and metastatic in the bladder)
Myxosarcoma (bladder)
Prostatic adenocarcinoma (urethra)
Rhabdomyosarcoma (bladder)
Endometrial adenocarcinoma (extraurinary invading and compressing
the
urethra)
Idiopathic: Up to 53% in some studies are as a result of unknown causes.
-4- DIAGNOSIS:
- Diagnosis is based on history given by the owner, a complete physical
examination by a veterinarian, laboratory tests and radiographs. Some
or all of the above may be necessary in order to make a diagnosis,
keeping in mind that a
cause may never be determined. Also one must remember that the cause
is usually
multiple in nature.
- All available information must be obtained in order to initiate
the best protocol for a successful treatment and prevention program.
TREATMENT:
- Within the scope of this article we will limit the discussion of
treatment too the three most common forms of FLUTD. Nonobstructive
hematuria and dysuria, Urolithiasis, and Obstruction with matrix-crystalline
urethral plugs.
-Nonobstuctive hematuria and dysuria: If a cause can be determined,
the appropriate therapy should be instituted, however, as in most
cases, the cause will be undetermined. In such a case a veterinarian
would initiate a broad spectrum of therapy. It could include all of
some of the following: antibiotics, corticosteroids, antispasmodics,
analgesics, and intravenous fluids
- Urolithiasis: If stones are found in the bladder, they should be
removed. That can be achieved by surgery, or if possible, by using
a special diet designed to dissolve stones made up of magnesium ammonium
phosphate (struvite). Again, if a cause can be determined the proper
therapy should also be initiated so as to prevent reoccurrence
- Obstruction with matrix-crystalline plugs: The obstruction should
be eliminated as soon as possible. This is best accomplished while
the cat is under anesthesia. If the obstruction has been for a considerable
amount of time there may be significant damage to the kidneys and
so blood should be drawn and the status of the kidneys evaluated.
Later additional blood should be tested to further study the kidneys.
An intravenous catheter would be instilled and the cat sedated. At
the same time as eliminating the obstruction intravenous fluids are
given as well as some additional medications. If a cause can be determined
appropriate medication would be given.
- In all cases canned food, fresh water,
clean litter boxes and the reduction or elimination of stress are
essential
-5- DIET CONSIDERATIONS:
- It is thought that one of the most significant problems associated
with this disease is the adequate consumption of water, both in treating
and preventing this condition. Canned food is 70+ % water and should
be fed. Fresh water should always be available and encouraged.
- Prescription diets often speed the recovery but may not be necessary
once the condition has resolved and any stress eliminated.
- Infection is a part of the problem and it is the nonobstructive
hematuria and
dysuria form a diet change may not be necessary. Eliminating the infection
and
canned food for a short period of time may be all that is needed.
- The majority of uroliths are either magnesium ammonium phosphate
(struvite) or calcium oxalate in composition.
- Struvite: Fresh water and canned food are essential so as to get
as much liquid into the animal, at least initially. Hill's Feline
S/D Diet is designed to dissolve struvite uroliths. The difficulty
is that they may take a very long time to do that and in the mean
time the cat is uncomfortable and may continue to exhibit symptoms
such as inappropriate urination etc. A canned diet that makes the
urine acid (pH around 6.3) is recommended as well as a diet low in
magnesium (less than 0.1% Dry Matter). To convert the as fed nutrient
content of a food to a dry matter basis divide the percentage of the
nutrient on an as fed basis by the percentage dry matter.
- Calcium Oxalate: Since the introduction of cat diets that are low
in magnesium and make the urine acid we have seen a reduction in the
incidence of struvite crystals as well as uroliths. However, there
has been an increased incidence of oxalate crystals and uroliths.
The ideal diet for a cat with the above problem is a canned diet that
maintains a more alkaline urine pH (6.6 to 6.8), is not as low in
magnesium. Potassium citrate is also useful as it has the ability
to form soluble salts with calcium.
-6- PREVENTION:
-Prevention is of utmost importance. Once a cat has had a problem
there is an increased chance that it will reoccur. This is thought
to be as a result of the many predisposing factors mentioned above
and the difficulty in controlling many of then.
- There are some animals that will require regular check-ups by a
veterinarian and specific medication as well as diet changes in order
to prevent the reoccurrence of this frustrating condition.
DIET CONSIDERATIONS:
· Diet can play a significant role in the prevention of FLUTD.
· Dry foods designed with a moderately low magnesium level
(not too low) and one that creates acid urine is ideal in most cases.
· Water consumption is the key to preventing the condition.
· Many recommend a combination of canned and dry diets in order
to help maintain adequate water intake.
· Stress is the most common cause of a reduction in water intake.
A major effort to determine and stress and eliminating it from the
environment is essential in preventing this condition. This can be
a difficult task.
· Most cats are able to return to a non-prescription diet,
however, there are those that will have difficulty unless maintained
on a specific prescription diet. Most of these animals do best on
canned or a combination of canned and dry.
Feline Lower Urinary Tract Disease can be a difficult and frustrating
condition for the pet owner as well as the veterinarian. It is essential
that all work together to resolve the problem and prevent it's reoccurrence.
