Does your Cat Have Lower Urinary Tract Disease?

Has your cat ever suffered from a disorder of the lower urinary
tract? Cats occasionally develop such problems, and the signs
include frequent urination, straining to urinate, bloody urine,
and at times inability to urinate.

In order to recognize and properly treat lower urinary tract
diseases (LUTDs), it is helpful to have a conceptual
understanding of the structure and function of the urinary
tract.

The normal urinary tract of a cat consists of two identical
kidneys. Urine formed by the kidneys passes into pliable tiny
muscular tubes called ureters. The ureter from each kidney is
connected to the urinary bladder. The bladder is like a balloon.
Rhythmic one-directional contractions of the ureter walls
transport urine formed by the kidneys into the bladder for
temporary storage.

Urine contained in the urinary bladder can be voided out of the
cat’s body through a tube larger than the ureters. This
cylindrical muscular tube is called the urethra. Urine is
normally retained in the bladder primarily by resistance in the
urethra caused by muscular tone. When the bladder becomes filled
with urine, however, the muscular wall of the bladder contracts
while the muscles in the urethral wall relax. The result is
complete ejection of urine stored in the bladder.

What are the clinical signs of diseases of the bladder and
urethra (or LUTDs)? They include difficult urination, bloody
urine, crystals in urine, and urethral obstruction that causes
complete inability to move urine from the bladder through the
urethra to the outside. These signs may have different causes.
Thus, there is a need for evaluation of each cat as an
individual to determine the proper form of treatment and
prevention. Possible causes of LUTDs include urinary stones,
bacterial and viral infections, birth defects, trauma, tumors,
and neuromuscular diseases. In more than 50 per cent of cats, it
may not be possible to determine the underlying cause(s).

To determine the underlying cause of LUTDs, the veterinarian
examines your cat, takes a medical history, and also performs
urinalyses (tests on the urine) on urine samples that have not
been altered by previous treatment. X-ray and ultrasound studies
may be needed to locate the exact site(s) of the problem and to
identify the causes of persistent or frequently recurring signs.
Identifying the site and cause of urethral obstruction is
especially important if some form of urethral surgery is being
considered. Although a variety of disorders can cause
obstruction of the urethra (especially in male cats), no matter
what the cause, complete obstruction results in dysfunction of
both kidneys that, if not quickly corrected, ultimately causes
death. Untreated cats usually die within 3 to 5 days after the
onset of obstruction.

Why is complete obstruction of the urethra life threatening?
Death results from retention of wastes, especially potassium and
metabolic acids, in the bloodstream. However, the retention can
be reversed by eliminating the obstruction and by correcting the
abnormalities in blood.

How should LUTDs be managed? Specific treatment of LUTDs should
be directed at the underlying causes, only some of which are
currently known. Of course, detecting known causes calls for
appropriate evaluation and diagnosis. In the case of a cat with
urethral obstruction, the treatment depends on the cause, site,
degree, and duration of the obstruction.

To treat a bacterial infection, a veterinarian should prescribe
appropriate antibiotics and eliminate or control problems in the
normal body defense system. For cases of urinary stones, either
medical dissolution protocols or surgical procedures may be
considered.

Treatment of difficult urination and bloody urine not associated
with identifiable causes remains a puzzle. Fortunately, the
signs of many cats with this form of LUTD usually subside on
their own. Unfortunately, the signs are unpredictably recurrent.
Because specific therapy is unavailable, veterinarians often
recommend therapy to treat the symptoms.

When evaluating the success of various treatments, we must be
careful. Many disorders in humans and animals are self-limiting,
meaning that our bodies’ defense systems eliminate the diseases.
Examples of self-limiting human diseases include the common cold
and many gastrointestinal problems involving vomiting and
diarrhea. In these cases, a treatment may seem beneficial as
long as it is not harmful. A similar situation occurs in some
cats with LUTDs.

However, your veterinarian may recommend changes in diet, litter
boxes, water availability, environment, or medications. Close
communication between you and your veterinarian regarding the
benefit or lack of benefit of any treatment trial will be
valuable after you closely observe your cat. Remember, there is
no “cure.” Also remember that inability of a cat to urinate is a
medical emergency that requires immediate veterinary attention.

The above is general veterinary information. Do not begin
any course of treatment without consulting your regular
veterinarian. All animals should be examined at least once every
12 months.