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 URINARY
TRACT INFECTION
How we
treat various urinary tract problems at our clinic, Followed by
articles and more information.
Note that sometimes
people say kidney infection when they really mean bladder
infection...and vice versa...but for the purposes of this page,
please understand the difference
GENERAL COMMENTS
Urinary
tract problems are common in both cats and dogs and the principles
of diagnosis and treatment are similar, so I'm going to combine the
discussion of these two species on this page. You can assume that
what I say about one species is pretty much true about the other
unless I make a point of telling you differently.
A
FEW COMMON MISCONCEPTIONS SET STRAIGHT
1.
Spaying and castrating a pet prior to their first heat does NOT make
them more prone to bladder infections and blockages. This idea is
something we thought to be true 20 years ago, but this idea has now
been proven to be false.
2. Cats are more
prone to getting bladder infections than dogs, perhaps because cats
originally evolved in desert climates and therefore have very
concentrated urine. Both female and male cats get bladder infections
but male cats are more likely to get urethral blockages because the
male urethra takes a turn inside the pelvis and because the urethra
inside the penis has a limited ability to expand.
WHAT TO EXPECT AT OUR HOSPITAL IF YOUR PET HAS A URINARY TRACT
INFECTION
Most of the time, it's pretty obvious that something is wrong with
your pet when they have a urinary tract problem. They strain to
urinate, or because of the inflammation and irritation, they don't
have normal control and pee in the house. They pee much more often.
Sometimes you can see blood in the urine.
But sometimes the
symptoms are not so obvious, and sometimes the cause of urinating in
the house is not an infection. Other causes include behavioural and
psychogenic problems, incontinence, side effects from medication,
excessive drinking for various reasons, metabolic diseases like
diabetes, and cancer. Or maybe from playing your new age soothing
sounds of nature "waterfall" CD too much.
EXAM AND HISTORY
Usually
there isn't much wrong discovered on physical exam; temperature,
lymph nodes, heart rate, external genitalia, and even bladder
palpation are fairly normal.
It's the
history of frequent urination, straining to urinate, and/or blood in
the urine that leads us to suspect a bladder infection.
Nonetheless, we
will perform a head to toe exam. Some things going through our minds
during this exam are...is the animal in heat?....has there been a
recent stress or water deprivation?...is this the first urinary
tract problem for this patient?...is there an underlying metabolic
problem involved like diabetes?...are there oral/gum infections?
(Cats and dogs spend a lot of time licking you know where, and if
they have a high oral bacteria count due to oral disease, they may
be seeding their urinary tract...another reason for dentistry!)
...Does the patient have a good vaccine history? (Protected from
leptospirosis)...is the patient also being treated with meds that
affect the urinary tract such as steroids?
All these questions
and more are factors and one of the reasons to trust such problems
to your veterinarian and not attempt home treatment.
Another reason not
to delay too long before getting professional help is that a bladder
infection left untreated for very long will lead to damage to the
urethral and bladder wall, causing it to lose it's super smooth
interior lining and ability to stretch and expand. This leads to
more likely future infections.
DIAGNOSTICS
It's fairly
expensive to run every test for every case suspected of a bladder
infection or other urinary tract problem, but depending on the age
of your pet, the severity of the symptoms, and whether or not your
pet has had previous problems will determine which of the following
tests will be recommended. On the other hand, an accurate diagnosis
based on these tests often prevents inadequate treatment which
sometimes leads to unnecessary discomfort and possible permanent
damage to the urinary tract system.
Here's a summary
and a few comments about the tests we are likely to recommend if
your pet is suspected of having either a lower urinary tract disease
or kidney disease.
COLLECTING THE URINE SAMPLE
There are 4 basic ways to collect urine, each with advantages and
disadvantages. Those 4 methods are 1. "Free catch" 2. Manual
expression under the influence of sedation 3. Via a urethral
catheter (under light sedation), and 4. Via cystocentesis which is
a fancy name for sticking a needle very carefully through the
abdominal wall into the bladder.
URINALYSIS
Once we collect the urine sample, we analysis it. Well dah. (Is
that how you spell dah?)
First we stick in
an inexpensive urine chemistry strip, which isn't very precise, but
does give us a crude warning if urine glucose, ketones, bilirubin,
leukocytes, occult blood, or excessive proteins are present. If any
of these are abnormal, that's a good clue about which disease is
present. A high urine protein, for example, could mean that there's
a lot of pus in the system...or that the kidney, which is supposed
to allow water and electrolytes to pass through it's filter is
damaged so that larger protein molecules are also passing through
the system.
The second part of
the urinalysis is to centrifuge the urine in order to separate the
water from any cells, molecules and other solids present, and to
examine the result under a microscope. One of the things we can see
under the microscope is pus. In the example about high urine
proteins in the paragraph above, if we don't find pus, then we can
correctly assume that the protein in the urine indicates kidney
disease, and more specifically, glomerulus disease. (The glomerulus
is the filtering system in the kidney, that when healthy, prevents
protein loss through the urine.)
WHAT ARE WE ABLE TO SEE UNDER THE MICROSCOPE?
-
White
Blood Cells (WBC's):
high numbers indicate infection from bacteria. Pus is the
macroscopic result of large numbers of white blood cells. Finding
pus in the urine confirms that there's a bladder infection (it
doesn't mean there aren't additional problems), it justifies the use
of antibiotics, and by later repeating the urinalysis, we can tell
whether or not the treatment was successful.
-
Red Blood Cells (RBC's):
a clue to the degree of inflammation and irritation.
-
Casts:
these are little plugs of dead cells from the kidney and large
numbers indicate kidney disease.
-
Crystals:
If present, we're warned that bladder stones may also be present or
that special diets may be needed to solve the problem.
-
Culture and
Sensitivity:
Another
thing we can do with the urine is culture it.
The disadvantage of
culturing is that it requires a fair amount of time, expense, and
attention to detail by everyone involved to get reliable culture
results. It's kind of like cooking a soufflÈ...everything has to be
just right...sterile collection of fresh urine, sterile transport on
culture broth at the right temperature, transfer to culture plates
and incubation for the proper amount of time at the proper
temperature, choosing useful sensitivity discs, and reliable,
readable records written by reliable lab techs. A lot can go
wrong, so don't be surprised if the results are discounted or need
to be repeated. Also, it takes about a week to get results back.
What makes all this
trouble worthwhile is that we learn which bacteria or combination of
bacteria is causing the trouble and which antibiotics are likely to
kill it. In addition, we also know that certain types of bacteria
(pseudomonas, for example) require not only special antibiotics but
also long term treatment for success.
Many vets and
physicians, me included, often skip this test and are successful in
simply choosing an antibiotic that usually works, but it's a little
gamble, and if we're wrong, then we have to start over, the patient
was in discomfort longer than needed, further damage was done to the
bladder and urethral lining that could be permanent, and we could
possibly be contributing to the problem of bacterial resistance to
antibiotics.
SPECIFIC GRAVITY
A screening test for kidney function
Another thing we do
with urine is check it's specific gravity. Pure water has a
specific gravity of zero (at sea level). At any rate, it's a
measure of how urine concentration. In other words...how much of
the urine is water and how much is made up of molecules, urea, and
the other waste materials the body has to eliminate each day. This
concentration changes normally within a range depending on all kinds
of factors like hydration, fever, medications etc, but numbers
outside the normal range tell us that something is wrong with the
kidneys, and this information combined with BUN and Creatinine
results tell us what kind of kidney disease the patient has.
-
Creatinine and BUN:
Common screening tests for kidney disease:
These blood tests
tell us whether or not the kidneys are working adequately, and when
the tests are repeated, they tell us whether or not kidney health is
improving or getting worse. To truly diagnose exactly what type and
extent of kidney disease a patient has often requires biopsy, ultra
sound, special x-rays or other newer imaging techniques, but we can
get a good idea with just creatinine and BUN results which are
relatively cheap and easy to do.
The only big
trouble with this pair of tests is that there can be a fair amount
of disease or kidney cell destruction going on and yet the test
results will be normal...
But if the results
aren't normal, we know that's significant.
-
Blood Glucose
Screen:
Used to check for diabetes if history or chem strip make us
suspicious.
-
CBC-Chemistry Panel:
Instead of doing BUN, Creatinine, and Blood Glucose as separate
tests, we often choose to run a complete chemistry panel which
includes these three test plus screening tests for liver disease,
pancreatitis, protein and globulin levels, and when a CBC (Complete
Blood Count) is added, we also learn about whether or not there is
anaemia, bleeding disorders, high white blood cell counts in the
blood and so forth.
Why do we
usually elect to do all these additional tests? Partly because the
cost for doing the whole panel is only slightly more, and secondly
because when an organ as important as the kidneys are diseased there
is often collateral disease in the rest of the body.
-
Radiographs and
special contrast radiographs:
I recommend radiographs for patients who have recurrent urinary
tract problems. Why? Because the problem is often a kidney,
bladder, or urethral stone. Radiographs will usually detect those
stones. In addition, radiographs are sometimes useful in detecting
cancers, urethral tears, diverticuli (little outpouches that harbour
bacteria), abnormalities in the size and shape of kidneys, ureter
damage, and thickened bladder walls.
-
Ultrasound:
Also useful in finding stones and tumours. Unfortunately, I don't
have an ultra sound machine at my practice, but many vets do.
-
Stone analysis:
This test is done only if we have a stone to test...usually after
surgical removal. There are several different types of stones, each
of which can be largely prevented if the right diet is chosen. Each
different type of stone has a different diet that is most likely to
control and prevent further disease. There's an article about
bladder stones below.
LIKELY TREATMENTS
(Of
course, other vets may do things differently)
-
TREATMENT OF THE
INFECTION IF PRESENT:
Antibiotics
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TREATMENT OF THE
URETHRAL AND BLADDER INFLAMMATION:
Glycoflex, glucosamine, MSM, and vitamin C to increase urethral
lubrication.
Antioxidants, Prednisone for
short periods, Phenobarbital for
smooth muscle relaxation.
Special Diets (see
below)
Anaesthesia -
catheterisation to flush stones out of urethra
Anaesthesia -
bladder surgery, stone removal etc
Laser and Ultra
Sound Stone Reduction - Not available at most clinics
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TREATMENT OF THE
WHOLE BODY:
This represents a
whole new subject. Disease is not an isolated event. If the rest of
the body is sickly from malnutrition, parasites, lack of exercise,
and maybe from lack of purpose and love, then disease is more likely
to flourish. When one organ system is sick, other organ systems are
affected. At any rate, we will address the patient as a whole and
make appropriate recommendations. They might include diet changes,
I.V. fluids and electrolytes, vitamins and minerals, and so forth.
-
TREATMENT FOR
DISEASES OF THE KIDNEY:
Let me get to this subject later. I usually refer pets with kidney
disease to a specialist to take advantage of their equipment and
expertise. Kidney disease is a major cause of death of older
pets...just like in humans...but so far, dialysis or kidney
transplantation are not commonly available for pets.
-
REFERRAL TO A
SPECIALIST:
for urethrostomy, ultra-sound, ureter or kidney surgery, and
consider for bladder surgery
-
SPECIAL DIETS:
Hill's C/D-S, C/D-O,S/D or Eukanuba special diets for the prevention
of urinary tract disease are the special diets we recommend for pets
with a history of recurring bladder infections...especially if
urinary crystals or stones were involved.
There are other
appropriate special diets available too...trust your
veterinarian...but remember that many over the counter diets that
claim things like "aids in the prevention of urinary tract disease"
may not be adequate.
URINARY
STONES _ CAUSE< TREATMENT AND PREVENTION
TEXTBOOK
OF VETERINARY INTERNAL MEDICINE
Client Information Series
-
Carl A. Osborne
DOES YOUT DOG OR CAT HAVE URINARY
STONES?
Perhaps you know them by the name kidney stones or bladder stones.
They form in the urinary tract of all kinds of animals and in
humans.
Urinary stones are
rock-hard structures. Stones in the urinary tract cause problems
because this system is designed to eliminate body wastes in liquid
form, whereas the intestinal tract is designed to eliminate wastes
in solid form.
In animals and in
humans, urinary stones are often called "calculi," from the Latin
word for stone. It is the same Latin word used in the mathematical
term calculus, as stones were at one time used for counting. The
word "lith" as in "urolith" is from the Greek word for stone. The
prefix "uro-" is a Greek term referring to the urinary tract. Thus,
a urolith is a urinary tract stone that may be located in the
kidneys (nephrolith; nephro is Greek for kidney), ureters (ureterolith),
urinary bladder (urocystolith), or urethra (ure-throlith)
Have you ever
wondered why stones form in the urinary tract?
The process is a
complicated one, but basically stones form because certain waste
products present in urine increase in concentration to a point at
which they precipitate as microscopic crystals. If these crystals
remain in the urinary tract and grow, they become large enough to
see with the unaided eye. With time, the stones may fill the space
in the urinary tract normally occupied by urine.
All urinary stones
contain two major components- minerals (which typically constitute
about 95 per cent of a stone) and non-mineral matrix (typically
about 5 per cent of a stone).
The matrix can be
thought of as a kind of mortar that may help to cement minerals
together. Because stones are composed primarily of minerals, their
number, location, and size can usually be detected by x-ray studies
or ultra-sound studies.
Do all urinary
stones have the same mineral composition? The answer is no. The most
common types of minerals in urinary stones formed by dogs and cats
are magnesium ammonium phosphate (also called struvite), calcium
oxalate, calcium phosphate, ammonium urate, cystine, and silica.
Sometimes stones contain more than one type of mineral. On occasion,
the centre of a urolith may be composed of one type of mineral (for
example, calcium oxalate). Whereas outer layers are composed of a
different mineral (especially struvite).
Determining the
types of minerals in stones is important because different mineral
types occur as a result of fundamentally different causes.
Therefore, urinary stones should not be considered a single disease
but rather a potential consequence of several underlying risk
factors. Treatment and/or prevention of stone formation depends on
identifying their mineral composition. In addition, evaluation of
your pet's diet, blood analysis, and urine composition analysis are
important steps in formulating recommendations for stone treatment
and prevention.
How can urinary
stones be effectively treated? Options include various types of
surgery and various types of nonsurgical therapy designed to
dissolve stones in the urinary tract.
Which treatment is
best? The risks and benefits of medical versus surgical therapy must
be considered for each pet. Complete obstruction of the flow of
urine through the urinary tract should be regarded as an emergency.
Although surgical
removal is an effective method that may immediately eliminate
uroliths, surgery alone is associated with several limitations,
including (1) persistence of the underlying causes of stones and
therefore a high rate of recurrence of uroliths after surgery, (2)
risks inherent in general anaesthesia and the type of surgery
performed, and (3) inability to remove all uroliths during surgery.
For these and other reasons (especially if the urolith is
asymptomatic), medical dissolution of some types of uroliths may be
considered.
The objectives of
medical dissolution of uroliths are to stop further stone growth
and/or to promote stone dissolution by correcting or controlling
underlying abnormalities. For medical dissolution therapy to be
effective, it must reduce the urine concentration of minerals that
have precipitated to form the stone. This usually involves a change
in diet and in addition often includes administration of specific
drug.
The size and number
of uroliths as such do not dictate the likelihood of response to
dissolution therapy. There has been success in dissolving uroliths
that are small and large, single and multiple. However, the rate of
dissolution is related to the size and surface area of the urolith
exposed to urine. Just as one large ice cube dissolves more slowly
than an equal volume of crushed ice, one large urolith dissolves
more slowly than an equal volume of many smaller uroliths.
Uroliths tend to
recur. Prevention of recurrent uroliths that reduces the need for
medical therapy and/or surgery is therefore cost effective. in
general, prevention strategies are designed to eliminate or control
the underlying causes of various types of uroliths. When causes
cannot be identified, preventive therapy is usually designed to
minimize risk factors associated with formation of all stones.
Recommendations commonly include dietary modifications and sometimes
administration of drugs.
CHRONIC AND/OR RECURRENT URINARY
TRACT INFECTIONS
Meanwhile, a few comments. Most urinary tract problems turn out to
be short-lived bladder infections that quickly respond to a short
course of antibiotics and anti-inflammatories. Many of our seminar
speakers on the subject go as far to say that many urinary tract
"infections" are not infections at all and would heal without
treatment.
But it's also true,
that some urinary tract infections are very persistent and difficult
to treat as well as very uncomfortable for the patient. And then
there are those cases that respond fairly well to medication...but
then come back; recurrent cases.
These are the kind
of cases where it's critical to spend the time, effort, and money to
do all the tests and radiographs discussed in the treatment section
above in order to:
Confirm that the
main problem is, in fact, an infection.
If it is an
infection, which bacteria is/are involved and which antibiotic is
best?
Is the owner giving
the medication correctly?
Do we need to give
the antibiotic for a longer period? Maybe as long as 6 weeks?
Is there some
reason there's an infection that needs to be corrected?
Possibilities include underlying kidney disease, underlying
bacterial infection of the blood, physical defects in the urinary
tract system, cancer, urinary crystals, stones, or damaged urethral
sphincter.
Is there some
hormonal, immune system, or metabolic problem going on that would
cause poor healing, persistence, or recurrence? Examples are being
in sexual heat, cystic ovaries, thyroid disease, Adrenal Gland
disease, and diabetes.
Is the patient on
some medication...especially steroids...that can be associated with
urinary tract infections?
There's usually a
reason that the problem is hard to cure, and if you're willing to
allow your vet to do adequate testing, we can usually discover the
cause and come up with a successful treatment plan
This information
has been kindly supplied by the Roger Ross, DVM,
Animal Pet
Doctor and the FoxNest Veterinary Hospital. Please
visit their website for more
interesting articles on pet health.
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