Crystals and malformed kidneys
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Crystals and malformed kidneys
Willowsmom 1/20/2012, 8:23 pm
I was reading about the Struvite and kidney issues. I just talked to Dorie's other vet,(she has two) and we were discussing the best treatment for Dorie. About 3 months ago I found blood in her urine, went to vet and she had a uti and crystals. Well 2 antibiotic treatments later the uti has cleared up. She has been on Hills s/d for the 3 months and the first ultrasound revealed crystals in bladder and kidney. It looked like a snow globe. We just had another ultrasound and x-ray, the crystals are still in the kidney. (I forgot to mention, her kidneys are malformed.) Not as many, but they are still there. The vet has discussed her case with other vets and specialists, some say remove kidney, others say no, leave it alone. After we discussed euthanasia, was not even an option at this point, (she is doing really great). I told him I was going to do more research and check on other options including herbal therapy, massage therapy, anything that may help. After she gets done with her last case of Hills s/d, he wants her to go on Hills c/d for the rest of her life. In a month we are going to do a urine test and keep up with getting ultrasound and x-ray to see if anything changes. If anyone has anything to share I would really appreciate it. I am new at this situation. Thank you in advance, Kat
Willowsmom-
- Number of posts : 8
Location : ohio
Article on struvites from Whole Dog Journal
northernwitch 1/20/2012, 8:28 pm
Part One: Preventing and treating struvite crystals
and stones.
Humans
aren’t the only ones who get kidney and bladder stones. Our dogs develop these
painful and dangerous conditions, too. But much of what is said and done about
canine urinary tract stone disease (also known as bladder stones, urolithiasis,
urinary stones, ureteral stones, urinary calculi, ureteral calculi, or urinary
calculus disease), including its causes and treatment, is either incorrect,
ineffective, or potentially harmful. Here’s the information you need in order
to make informed decisions on behalf of your best friend.
Most
canine uroliths, or bladder stones, fall into six categories, depending on
their mineral composition: • Magnesium ammonium phosphate (also called
struvites)
• Calcium
oxalate
•
Ammonium urate or uric acid
• Cystine
• Calcium
phosphate
• Silica
There are
also compound or mixed stones consisting of a core mineral surrounded by
smaller amounts of another mineral, most commonly a struvite core surrounded by
calcium phosphate. In veterinary reports, the terms stone, urolith, and
calculus (its plural is calculi) are used synonymously.
Because
different stones require entirely different treatment -and often completely
opposite treatment -it’s critical to identify the type of stone accurately.
Without removing a stone there is no way to know for sure, but a good guess can
be made based on urinary pH; the dog’s age, breed, and sex; type of crystals,
if present; radiographic density (how well the stones can be seen on x-ray);
whether infection is present; and certain blood test abnormalities.
Between
1981 and 2007, the Minnesota Urolith Center at the University of Minnesota’s
College of Veterinary Medicine analyzed 350,803 canine uroliths. The highest
percentage came from mixed breeds (25 percent), Miniature Schnauzers (12
percent), Shih Tzus (9 percent), Bichons Frises (7 percent), Cocker Spaniels (5
percent), and Lhasa Apsos (4 percent). The remaining 38 percent were collected
from 154 different breeds.
Veterinary
studies conducted around the world on millions of urinary stones show similar
demographics. Although kidney and bladder stones can afflict dogs of both
sexes, all breeds, and all ages, those at greatest risk are small, female,
between the ages of 4 and 8, and prone to bladder infections. Although male
dogs develop fewer stones, the condition is more dangerous to them because of
their anatomy. Stones are more likely to cause blockages in the male’s longer,
narrower urethra.
In 1981,
78 percent of all uroliths tested at the Minnesota Urolith Center were
struvites and only 5 percent were calcium oxalate stones, but by 2006 the
struvite occurrence had fallen to 39 percent while the incidence of calcium
oxalate stones rose to 41 percent. Researchers investigating the trend have not
discovered a reason for the change but are exploring demographic risk factors
such as breed, age, gender anatomy, and genetic predisposition along with
environmental risk factors such as sources of food, water, exposure to certain
drugs, and living conditions.
Bladder
stones
When bladder stones form, their minerals precipitate out in the urine as
microscopic crystals. If the crystals unite, they form small grains of
sand-like material. Once grains develop, additional precipitation can lead the
crystals to adhere together, creating stones. Some stones measure up to 3 or 4
inches in diameter. Problems develop when stones interfere with urination.
Some dogs
with stones never develop symptoms and their stones are never diagnosed or are
discovered during routine physical exams when the abdomen is palpated. X-rays,
which can be used to confirm the diagnosis, reveal stones as obvious white
circles unless they are radiolucent (invisible to X-rays), in which case a dye
injected into the bladder makes them visible.
Symptoms
of stones can include blood in the urine (hematuria), the frequent passing of
small amounts of urine, straining to produce urine while holding the position
much longer than usual, licking the genital area more than usual, painful
urination (the dog yelps from discomfort), cloudy and foul-smelling urine that
may contain blood or pus, tenderness in the bladder area, pain in the lower
back, fever, and lethargy. If a stone blocks the flow of urine, its
complications can be fatal.
When
surgery is necessary, uroliths are removed by a cystotomy, a procedure that
opens the bladder. Stones lodged in the urethra can be flushed into the bladder
and removed. Stones that are small enough to pass in the urine can be removed
in a nonsurgical procedure called urohydropropulsion. A catheter is used to fill
the sedated dog’s bladder with a saline solution and the bladder is squeezed to
expel the stones through the urethra. Other procedures are used for more
complicated cases.
All dogs
who have formed a urolith are considered at increased risk for a recurrence.
According to Dennis J. Chew, in a paper delivered at the 2004 Small Animal
Proceedings Symposium of the American College of Veterinary Surgeons, “Water
may be the most important nutrient to prevent recurrence of uroliths. Increased
water intake is the cornerstone of therapy for urolithiasis in both human and
veterinary medicine. Increasing water intake to dilute urine and increase
frequency of urination is an important part of treatment. Decreasing the
concentration of potential stone-forming minerals in urine and increasing the
frequency of voiding are the key elements of therapy to reduce the risk of
formation of a new urolith.”
It’s easy
to interest most dogs in drinking more fluids by making sure that plain water
is available at all times, adding broth and other flavor enhancers to water in
an additional bowl, and adding water or broth to food. Just as important is the
opportunity to urinate several times a day. Stones and crystals form in
supersaturated urine, which can occur when dogs have to hold their urine for
long periods.
This
month, we’ll discuss struvite uroliths. Calcium oxalate uroliths will be
discussed in the next issue.
Struvite
stones
Struvite uroliths belong to the magnesium ammonium phosphate (MAP) category.
Struvites are also known as triple phosphate uroliths, a term dating from an
old, incorrect assumption that the struvite crystal’s phosphate ion was bound
to three positive ions instead of just magnesium and ammonium. Although
struvites can develop in the kidneys, where they are called nephroliths, the
vast majority are bladder stones. About 85 percent of all struvite stones are
found in female dogs and only 15 percent are found in males.
Struvite
stones usually form when large amounts of crystals are present in combination
with a urinary tract infection from urease-producing bacteria such as
Staphylococcus or Proteus. Urease is an enzyme that catalyzes the hydrolysis of
urea, forming ammonia and carbon dioxide. It contributes to struvite stone
formation as well as alkaline (high-pH) urine.
Caregivers
and veterinarians obviously want to prevent and treat struvites as effectively
as possible. But what works and what doesn’t is a topic of confusion.
Fact or
fiction?
All of the following statements are believed by many veterinarians and their
clients. Yet none of them are true. Which have you heard before?
1.
Urinary struvite crystals represent disease and require treatment.
2.
Struvite crystals require a change in diet, usually to a prescription diet like
c/d, u/d, or s/d.
3. Dogs
prone to forming struvite stones should be kept on a special diet for life.
4. The
most important treatment for dogs with a history of struvite stones is a
low-protein diet.
Here’s
why these common beliefs are misconceptions.
1. The presence of urinary struvite
crystals alone does not represent disease and does not require treatment. These
crystals can be found in the urine of an estimated 40 to 44 percent of all
healthy dogs and are not a cause for concern unless accompanied by signs of a
urinary tract infection. According to the Merck Veterinary Manual (2005),
“Struvite crystals are commonly observed in canine and feline urine. Struvite
crystalluria in dogs is not a problem unless there is a concurrent bacterial
urinary tract infection with a urease-producing microbe. Without an infection,
struvite crystals in dogs will not be associated with struvite urolith
formation.”(Our emphasis.)
Whether
your struvite-crystal dog has a urinary tract infection is the key question.
Researchers estimate that more than 98 percent of all struvite stones are
associated with infection. Failing to eradicate the original infection and
prevent new bacterial infections is the main reason struvite uroliths recur. A
recurrence rate of 21 percent was recorded in one study, but the risk can be
significantly reduced through increased surveillance and appropriate
antimicrobial treatment. In one study, dogs were infected with an experimental
Staphylococcal urinary tract infection, and their infection-induced struvites
grew large enough to be seen on X-rays within two to eight weeks.
2. Struvite crystals do not require
a change in diet. Because struvite crystals do not pose a problem unless the
dog has a urinary tract infection, there is no required treatment for crystals,
including dietary changes. If the dog does have a urinary tract infection, a
prescription dog food will not cure it.
If your
veterinarian finds struvite crystals in the urine and suggests a diet change,
you’d be well advised to find a new vet. You have to wonder how many other
things he or she is misinformed about. It isn’t just a case of not keeping up
with newer research; this recommendation is just plain wrong.
3. Dogs prone to forming struvite
stones should not be kept on a special diet for life. Struvites almost always
form because of infections, for which dogs with a history of stones should be
closely monitored and properly treated. No long-term dietary change is
required, nor will a special diet prevent the formation of infection-induced
struvites. However, short-term changes may help speed the dissolution of
stones.
4. Low-protein diets do not prevent
stone formation. A low-protein diet can speed the dissolution of struvite
stones -when accompanied by appropriate antibiotic treatment -but it is not
necessary for the prevention of struvite formation in dogs who are prone to
this problem. For almost all dogs, controlling infections will prevent more
stones from forming.
The
lowdown on low-protein
Several prescription dog foods are marketed as a treatment for struvite
crystals and struvite stones. These are called calculolytic foods or diets, and
nearly all of them are severely protein-restricted, phosphate-restricted,
magnesium-restricted, highly acidifying, and supplemented with salt to increase
the patient’s thirst and fluid consumption.
While a
low-protein diet is not required to dissolve struvite stones, it can speed
their dissolution (when accompanied by appropriate antibiotic treatment).
Protein provides urea, which bacteria convert or “hydrolyze”into ammonia, one
of the struvite building blocks. However, this approach is not a long-term
solution and will not prevent the formation of infection-induced stones.
Feeding a low-protein diet to an adult dog to help dissolve stones is
acceptable for short periods. Because they are not nutritionally complete,
however, low-protein foods are harmful to adult dogs if used for more than a
few months, and they should never be fed to puppies.
If stones
are not present, there is no reason to feed a low-protein diet. According to
Dr. Chew, “No studies exist to show that a specific diet is helpful for the
prevention of infection-related stone development.”
In
general, the benefits of a meat-based diet far outweigh the risks posed by protein’s
ammonia generation. Plus, by feeding your dog a home-prepared diet of fresh
ingredients, you can provide food that is higher in quality and much more to
your dog’s liking than diets that come out of cans or packages.
Other
prescription pet food strategies -such as keeping the diet low in fiber so that
fluids are not lost through the intestines, using highly digestible ingredients
for the same reason, and increasing the dog’s fluid intake by adding salt to
the diet -can be better accomplished with a home-prepared diet and management
techniques that encourage the dog to drink more water. The more concentrated
the urine, the more saturated it becomes with minerals that can precipitate
out, so extra fluids, which dilute the urine, reduce the risk.
Urinary
acidifiers are not used to dissolve or prevent stones caused by urinary tract
infections, since acidification does not help while an infection is present.
The
importance of testing
It’s important to know that urinalysis can’t always detect a bladder infection;
urinalysis may appear normal as frequently as 20 percent of the time when a
urinary tract infection is present.
For this
reason, if your dog shows possible signs of infection, you need to request a
“urinary culture and sensitivity test.”This will verify the diagnosis (in some
cases the problem is something other than an infection) and, if it is an
infection, it will reveal which antibiotic will be most effective for
treatment. Using an ineffective antibiotic not only harms the patient by
delaying proper treatment, but also contributes to the spread of drug-resistant
bacteria. Antibiotic therapy must be continued as long as struvite stones are
present, since the stones harbor bacteria that are released as the stones
dissolve.
Dogs who
are prone to frequent infections may need longer antibiotic therapy -of at
least four to six weeks -to completely eradicate the infection. Some dogs need
continuous or “pulsed”antibiotic therapy to prevent recurring infections. A few
may need surgery to correct structural defects that make them prone to
infection, such as a recessed vulva. This condition usually corrects itself
following first heat but may continue to cause problems for females who are
spayed prior to their first heat.
Ureaplasma
bacteria, which can cause struvite stones, will not show up on a regular urine
culture, but you can request a special culture to look for this type of
bacteria. This should be done before one assumes that the patient’s struvites
are sterile (see “Sterile Struvites,”page 13) rather than infection-induced.
Follow-up
tests will show whether the therapy your dog received, such as antibiotics from
a conventional veterinarian or an alternative infection-fighting treatment from
a holistic vet, was effective. You want to be sure that the treatment worked
and that the infection isn’t coming back. For dogs with a history of forming
struvite stones, or who suffer from multiple urinary tract infections, cultures
should be repeated a few days after treatment ends and then periodically, such
as monthly for a while and then at longer intervals, to be sure the infection is
completely cleared.
At-home
prevention
To keep your dog healthy, it’s important to prevent the conditions -especially,
urinary tract infections -that can lead to stone formation.
Monitoring
your dog’s urinary pH at home will alert you to any recurring bladder
infection. (Sources for pH test strips that cover the range needed are listed
on the next page.) The numbers refer to acidity and alkalinity, with 7
considered neutral (neither acid nor alkaline). Numbers less than 7 indicate
acidity, and the lower the number, the more acid the substance. Numbers greater
than 7 indicate alkalinity, and the higher the number, the more alkaline the
substance. Most healthy dogs have a neutral to slightly acid urinary pH between
5.5 and 7.0.
Because
urinary pH varies throughout the day, test your dog’s urine at the same time
each day to determine her “normal”pH. The best time to do this is first thing
in the morning, before she eats. Urine should be tested before it hits the
ground. You can collect some in a paper cup or simply hold a pH test strip in
the stream. An advantage to paper cup collection is that you can also check the
urine for blood, cloudiness, and other indications of infection.
The
urinary tract infections that cause struvite crystals to become uroliths have
an alkalizing effect, raising urinary pH to as much as 8.0 or 8.5. If your
dog’s urinary pH jumps from acid to alkaline, contact your veterinarian.
Other
preventive measures include giving your dog cranberry capsules, probiotics, and
vitamin C.
Cranberry
doesn’t cure existing infections, but it mechanically prevents bacteria from
adhering to the tissue that lines the bladder and urinary tract. Because they
are continuously washed out of the system, bacteria don’t have an opportunity
to create new infections. Cranberry capsules are easier to use and more
effective than juice, since they are far more concentrated. On product labels,
the terms cranberry, cranberry juice, cranberry extract, and cranberry
concentrate tend to be used interchangeably.
If your
cranberry capsules are a veterinary product, follow label directions. If
they’re designed for humans, adjust the dosage for your dog’s weight by
assuming that the label dose applies to a human weighing 100-120 pounds. Giving
cranberry in divided doses, such as twice or three times during the day, will
make this preventive treatment more effective.
Probiotics
are the body’s first line of defense against infection, and the more beneficial
bacteria in your dog’s digestive tract, the better. Probiotics are routinely
used by a growing number of medical doctors and veterinarians to treat urinary
tract and vaginal infections in women and pets.
Several
brands of probiotics are made especially for dogs. Because antibiotics destroy
beneficial as well as harmful bacteria, the use of probiotic supplements after
treatment with antibiotics helps restore the body’s population of beneficial
bacteria. (See “Probing Probiotics,”Whole Dog Journal August 2006 for more
information.) Many veterinarians recommend vitamin C for dogs who are prone to
bladder infections and struvite stones because of its anti-inflammatory
effects. Dogs (unlike humans) manufacture their own vitamin C, but the amount
they produce may not meet their needs if they are under stress or fighting
infection.
The ascorbate
form of vitamin C is most often recommended for dogs, as it may be better
absorbed and is less prone to causing gastrointestinal upset. Calcium ascorbate
and sodium ascorbate are available in generic forms as a powder, but the most
popular form is a product called Ester-C, which contains calcium ascorbate and
vitamin C metabolites.
Veterinary
recommendations range from 250 mg twice per day for every 15 to 30 pounds of
body weight up to a maximum of 1,000 mg twice a day for large dogs. Because
vitamin C can cause diarrhea, start with small doses and increase gradually.
The maximum amount your dog can tolerate without the diarrhea side effect is
called her “bowel tolerance”dose.
The herb
uva ursi (Arctostaphylos uva-ursi) is used in many herbal blends for bladder
infections because of its antibacterial properties. Uva ursi is best used for
short periods rather than for months at a time as it can irritate the kidneys.
The dosage for this herb depends on the individual blend and how it was
prepared. Follow label directions for products formulated for dogs; adjust the
dosage of products meant for humans by weight, assuming the human’s weight at
100 to 120 pounds.
While
adding salt to your dog’s food is an effective way to encourage drinking more
fluids for dogs who don’t tend to drink enough, consider switching from refined
table salt to unrefined sea salt, which is sold in natural food markets and
contains dozens of minerals and trace elements that are not present in refined
salt.
Since
most homemade diets are low in salt compared to commercial foods, the amount of
salt to add will depend on the diet you feed. Start by adding a pinch of salt
(small for a small dog, larger for a large dog) to your dog’s food and watch to
see if it makes her more thirsty. Increase the amount by a pinch at a time
until she is drinking more than usual.
Traditional
broth or stock is easy to make at home by simmering chicken, beef, or other
bones in water overnight or for 24 to 36 hours. If desired, add carrots and
other vegetables. Replace evaporating water as needed. The longer the simmer,
the more nutritionally dense the broth and the more interesting it is likely to
be to your dog. Broth can be used as a flavor enhancer when strained and added
to food or given in addition to water. Be sure to provide plain drinking water
at all times.
Struvite
stones can make any dog miserable, but by understanding how and why they occur
and by taking the preventive measures described here, you can be sure that your
dog lives a happy, stone-free life.
Next
month: Calcium
oxalate uroliths, America’s most common canine urinary stones.
CJ
Puotinen is the
author of The Encyclopedia of Natural Pet Care and other holistic health books.
She lives in Montana, and is a frequent contributor to WDJ.
San Francisco
Bay Area resident Mary Straus has spent more than a decade investigating and
writing about canine health and nutrition topics for her website, DogAware.com
and stones.
Humans
aren’t the only ones who get kidney and bladder stones. Our dogs develop these
painful and dangerous conditions, too. But much of what is said and done about
canine urinary tract stone disease (also known as bladder stones, urolithiasis,
urinary stones, ureteral stones, urinary calculi, ureteral calculi, or urinary
calculus disease), including its causes and treatment, is either incorrect,
ineffective, or potentially harmful. Here’s the information you need in order
to make informed decisions on behalf of your best friend.
 Struvite (magnesium ammonium phosphate or “triple phosphate”) crystals in polarized light (total magnification 112x). Struvite crystals are common in dogs and don’t cause problems until they unite to form stones that interfere with urination; generally, this happens only when the dog has a urinary tract infection. |
Most
canine uroliths, or bladder stones, fall into six categories, depending on
their mineral composition: • Magnesium ammonium phosphate (also called
struvites)
• Calcium
oxalate
•
Ammonium urate or uric acid
• Cystine
• Calcium
phosphate
• Silica
There are
also compound or mixed stones consisting of a core mineral surrounded by
smaller amounts of another mineral, most commonly a struvite core surrounded by
calcium phosphate. In veterinary reports, the terms stone, urolith, and
calculus (its plural is calculi) are used synonymously.
Because
different stones require entirely different treatment -and often completely
opposite treatment -it’s critical to identify the type of stone accurately.
Without removing a stone there is no way to know for sure, but a good guess can
be made based on urinary pH; the dog’s age, breed, and sex; type of crystals,
if present; radiographic density (how well the stones can be seen on x-ray);
whether infection is present; and certain blood test abnormalities.
Between
1981 and 2007, the Minnesota Urolith Center at the University of Minnesota’s
College of Veterinary Medicine analyzed 350,803 canine uroliths. The highest
percentage came from mixed breeds (25 percent), Miniature Schnauzers (12
percent), Shih Tzus (9 percent), Bichons Frises (7 percent), Cocker Spaniels (5
percent), and Lhasa Apsos (4 percent). The remaining 38 percent were collected
from 154 different breeds.
Veterinary
studies conducted around the world on millions of urinary stones show similar
demographics. Although kidney and bladder stones can afflict dogs of both
sexes, all breeds, and all ages, those at greatest risk are small, female,
between the ages of 4 and 8, and prone to bladder infections. Although male
dogs develop fewer stones, the condition is more dangerous to them because of
their anatomy. Stones are more likely to cause blockages in the male’s longer,
narrower urethra.
In 1981,
78 percent of all uroliths tested at the Minnesota Urolith Center were
struvites and only 5 percent were calcium oxalate stones, but by 2006 the
struvite occurrence had fallen to 39 percent while the incidence of calcium
oxalate stones rose to 41 percent. Researchers investigating the trend have not
discovered a reason for the change but are exploring demographic risk factors
such as breed, age, gender anatomy, and genetic predisposition along with
environmental risk factors such as sources of food, water, exposure to certain
drugs, and living conditions.
Bladder
stones
When bladder stones form, their minerals precipitate out in the urine as
microscopic crystals. If the crystals unite, they form small grains of
sand-like material. Once grains develop, additional precipitation can lead the
crystals to adhere together, creating stones. Some stones measure up to 3 or 4
inches in diameter. Problems develop when stones interfere with urination.
Some dogs
with stones never develop symptoms and their stones are never diagnosed or are
discovered during routine physical exams when the abdomen is palpated. X-rays,
which can be used to confirm the diagnosis, reveal stones as obvious white
circles unless they are radiolucent (invisible to X-rays), in which case a dye
injected into the bladder makes them visible.
Symptoms
of stones can include blood in the urine (hematuria), the frequent passing of
small amounts of urine, straining to produce urine while holding the position
much longer than usual, licking the genital area more than usual, painful
urination (the dog yelps from discomfort), cloudy and foul-smelling urine that
may contain blood or pus, tenderness in the bladder area, pain in the lower
back, fever, and lethargy. If a stone blocks the flow of urine, its
complications can be fatal.
When
surgery is necessary, uroliths are removed by a cystotomy, a procedure that
opens the bladder. Stones lodged in the urethra can be flushed into the bladder
and removed. Stones that are small enough to pass in the urine can be removed
in a nonsurgical procedure called urohydropropulsion. A catheter is used to fill
the sedated dog’s bladder with a saline solution and the bladder is squeezed to
expel the stones through the urethra. Other procedures are used for more
complicated cases.
All dogs
who have formed a urolith are considered at increased risk for a recurrence.
According to Dennis J. Chew, in a paper delivered at the 2004 Small Animal
Proceedings Symposium of the American College of Veterinary Surgeons, “Water
may be the most important nutrient to prevent recurrence of uroliths. Increased
water intake is the cornerstone of therapy for urolithiasis in both human and
veterinary medicine. Increasing water intake to dilute urine and increase
frequency of urination is an important part of treatment. Decreasing the
concentration of potential stone-forming minerals in urine and increasing the
frequency of voiding are the key elements of therapy to reduce the risk of
formation of a new urolith.”
It’s easy
to interest most dogs in drinking more fluids by making sure that plain water
is available at all times, adding broth and other flavor enhancers to water in
an additional bowl, and adding water or broth to food. Just as important is the
opportunity to urinate several times a day. Stones and crystals form in
supersaturated urine, which can occur when dogs have to hold their urine for
long periods.
 Monitoring the pH of your dog’s urine can alert you to a recurrence of a urinary tract infection. Collecting a sample to test is not difficult; use a clean paper cup and a pair of tongs or a “pick up” tool. Or, just slide a clean dish under your dog as she urinates! You need to catch only a few drops to test. |
This
month, we’ll discuss struvite uroliths. Calcium oxalate uroliths will be
discussed in the next issue.
Struvite
stones
Struvite uroliths belong to the magnesium ammonium phosphate (MAP) category.
Struvites are also known as triple phosphate uroliths, a term dating from an
old, incorrect assumption that the struvite crystal’s phosphate ion was bound
to three positive ions instead of just magnesium and ammonium. Although
struvites can develop in the kidneys, where they are called nephroliths, the
vast majority are bladder stones. About 85 percent of all struvite stones are
found in female dogs and only 15 percent are found in males.
Struvite
stones usually form when large amounts of crystals are present in combination
with a urinary tract infection from urease-producing bacteria such as
Staphylococcus or Proteus. Urease is an enzyme that catalyzes the hydrolysis of
urea, forming ammonia and carbon dioxide. It contributes to struvite stone
formation as well as alkaline (high-pH) urine.
Caregivers
and veterinarians obviously want to prevent and treat struvites as effectively
as possible. But what works and what doesn’t is a topic of confusion.
Fact or
fiction?
All of the following statements are believed by many veterinarians and their
clients. Yet none of them are true. Which have you heard before?
1.
Urinary struvite crystals represent disease and require treatment.
2.
Struvite crystals require a change in diet, usually to a prescription diet like
c/d, u/d, or s/d.
3. Dogs
prone to forming struvite stones should be kept on a special diet for life.
4. The
most important treatment for dogs with a history of struvite stones is a
low-protein diet.
Here’s
why these common beliefs are misconceptions.
1. The presence of urinary struvite
crystals alone does not represent disease and does not require treatment. These
crystals can be found in the urine of an estimated 40 to 44 percent of all
healthy dogs and are not a cause for concern unless accompanied by signs of a
urinary tract infection. According to the Merck Veterinary Manual (2005),
“Struvite crystals are commonly observed in canine and feline urine. Struvite
crystalluria in dogs is not a problem unless there is a concurrent bacterial
urinary tract infection with a urease-producing microbe. Without an infection,
struvite crystals in dogs will not be associated with struvite urolith
formation.”(Our emphasis.)
Whether
your struvite-crystal dog has a urinary tract infection is the key question.
Researchers estimate that more than 98 percent of all struvite stones are
associated with infection. Failing to eradicate the original infection and
prevent new bacterial infections is the main reason struvite uroliths recur. A
recurrence rate of 21 percent was recorded in one study, but the risk can be
significantly reduced through increased surveillance and appropriate
antimicrobial treatment. In one study, dogs were infected with an experimental
Staphylococcal urinary tract infection, and their infection-induced struvites
grew large enough to be seen on X-rays within two to eight weeks.
2. Struvite crystals do not require
a change in diet. Because struvite crystals do not pose a problem unless the
dog has a urinary tract infection, there is no required treatment for crystals,
including dietary changes. If the dog does have a urinary tract infection, a
prescription dog food will not cure it.
If your
veterinarian finds struvite crystals in the urine and suggests a diet change,
you’d be well advised to find a new vet. You have to wonder how many other
things he or she is misinformed about. It isn’t just a case of not keeping up
with newer research; this recommendation is just plain wrong.
3. Dogs prone to forming struvite
stones should not be kept on a special diet for life. Struvites almost always
form because of infections, for which dogs with a history of stones should be
closely monitored and properly treated. No long-term dietary change is
required, nor will a special diet prevent the formation of infection-induced
struvites. However, short-term changes may help speed the dissolution of
stones.
4. Low-protein diets do not prevent
stone formation. A low-protein diet can speed the dissolution of struvite
stones -when accompanied by appropriate antibiotic treatment -but it is not
necessary for the prevention of struvite formation in dogs who are prone to
this problem. For almost all dogs, controlling infections will prevent more
stones from forming.
The
lowdown on low-protein
Several prescription dog foods are marketed as a treatment for struvite
crystals and struvite stones. These are called calculolytic foods or diets, and
nearly all of them are severely protein-restricted, phosphate-restricted,
magnesium-restricted, highly acidifying, and supplemented with salt to increase
the patient’s thirst and fluid consumption.
While a
low-protein diet is not required to dissolve struvite stones, it can speed
their dissolution (when accompanied by appropriate antibiotic treatment).
Protein provides urea, which bacteria convert or “hydrolyze”into ammonia, one
of the struvite building blocks. However, this approach is not a long-term
solution and will not prevent the formation of infection-induced stones.
Feeding a low-protein diet to an adult dog to help dissolve stones is
acceptable for short periods. Because they are not nutritionally complete,
however, low-protein foods are harmful to adult dogs if used for more than a
few months, and they should never be fed to puppies.
If stones
are not present, there is no reason to feed a low-protein diet. According to
Dr. Chew, “No studies exist to show that a specific diet is helpful for the
prevention of infection-related stone development.”
In
general, the benefits of a meat-based diet far outweigh the risks posed by protein’s
ammonia generation. Plus, by feeding your dog a home-prepared diet of fresh
ingredients, you can provide food that is higher in quality and much more to
your dog’s liking than diets that come out of cans or packages.
Other
prescription pet food strategies -such as keeping the diet low in fiber so that
fluids are not lost through the intestines, using highly digestible ingredients
for the same reason, and increasing the dog’s fluid intake by adding salt to
the diet -can be better accomplished with a home-prepared diet and management
techniques that encourage the dog to drink more water. The more concentrated
the urine, the more saturated it becomes with minerals that can precipitate
out, so extra fluids, which dilute the urine, reduce the risk.
Urinary
acidifiers are not used to dissolve or prevent stones caused by urinary tract
infections, since acidification does not help while an infection is present.
The
importance of testing
It’s important to know that urinalysis can’t always detect a bladder infection;
urinalysis may appear normal as frequently as 20 percent of the time when a
urinary tract infection is present.
For this
reason, if your dog shows possible signs of infection, you need to request a
“urinary culture and sensitivity test.”This will verify the diagnosis (in some
cases the problem is something other than an infection) and, if it is an
infection, it will reveal which antibiotic will be most effective for
treatment. Using an ineffective antibiotic not only harms the patient by
delaying proper treatment, but also contributes to the spread of drug-resistant
bacteria. Antibiotic therapy must be continued as long as struvite stones are
present, since the stones harbor bacteria that are released as the stones
dissolve.
 Urinary tract infections that cause struvite crystals to become uroliths can raise urinary pH to 8.0 or 8.5. Contact your vet if your dog’s urinary pH jumps from acid to alkaline. |
Dogs who
are prone to frequent infections may need longer antibiotic therapy -of at
least four to six weeks -to completely eradicate the infection. Some dogs need
continuous or “pulsed”antibiotic therapy to prevent recurring infections. A few
may need surgery to correct structural defects that make them prone to
infection, such as a recessed vulva. This condition usually corrects itself
following first heat but may continue to cause problems for females who are
spayed prior to their first heat.
Ureaplasma
bacteria, which can cause struvite stones, will not show up on a regular urine
culture, but you can request a special culture to look for this type of
bacteria. This should be done before one assumes that the patient’s struvites
are sterile (see “Sterile Struvites,”page 13) rather than infection-induced.
Follow-up
tests will show whether the therapy your dog received, such as antibiotics from
a conventional veterinarian or an alternative infection-fighting treatment from
a holistic vet, was effective. You want to be sure that the treatment worked
and that the infection isn’t coming back. For dogs with a history of forming
struvite stones, or who suffer from multiple urinary tract infections, cultures
should be repeated a few days after treatment ends and then periodically, such
as monthly for a while and then at longer intervals, to be sure the infection is
completely cleared.
At-home
prevention
To keep your dog healthy, it’s important to prevent the conditions -especially,
urinary tract infections -that can lead to stone formation.
Monitoring
your dog’s urinary pH at home will alert you to any recurring bladder
infection. (Sources for pH test strips that cover the range needed are listed
on the next page.) The numbers refer to acidity and alkalinity, with 7
considered neutral (neither acid nor alkaline). Numbers less than 7 indicate
acidity, and the lower the number, the more acid the substance. Numbers greater
than 7 indicate alkalinity, and the higher the number, the more alkaline the
substance. Most healthy dogs have a neutral to slightly acid urinary pH between
5.5 and 7.0.
Because
urinary pH varies throughout the day, test your dog’s urine at the same time
each day to determine her “normal”pH. The best time to do this is first thing
in the morning, before she eats. Urine should be tested before it hits the
ground. You can collect some in a paper cup or simply hold a pH test strip in
the stream. An advantage to paper cup collection is that you can also check the
urine for blood, cloudiness, and other indications of infection.
The
urinary tract infections that cause struvite crystals to become uroliths have
an alkalizing effect, raising urinary pH to as much as 8.0 or 8.5. If your
dog’s urinary pH jumps from acid to alkaline, contact your veterinarian.
Other
preventive measures include giving your dog cranberry capsules, probiotics, and
vitamin C.
Cranberry
doesn’t cure existing infections, but it mechanically prevents bacteria from
adhering to the tissue that lines the bladder and urinary tract. Because they
are continuously washed out of the system, bacteria don’t have an opportunity
to create new infections. Cranberry capsules are easier to use and more
effective than juice, since they are far more concentrated. On product labels,
the terms cranberry, cranberry juice, cranberry extract, and cranberry
concentrate tend to be used interchangeably.
If your
cranberry capsules are a veterinary product, follow label directions. If
they’re designed for humans, adjust the dosage for your dog’s weight by
assuming that the label dose applies to a human weighing 100-120 pounds. Giving
cranberry in divided doses, such as twice or three times during the day, will
make this preventive treatment more effective.
Probiotics
are the body’s first line of defense against infection, and the more beneficial
bacteria in your dog’s digestive tract, the better. Probiotics are routinely
used by a growing number of medical doctors and veterinarians to treat urinary
tract and vaginal infections in women and pets.
Several
brands of probiotics are made especially for dogs. Because antibiotics destroy
beneficial as well as harmful bacteria, the use of probiotic supplements after
treatment with antibiotics helps restore the body’s population of beneficial
bacteria. (See “Probing Probiotics,”Whole Dog Journal August 2006 for more
information.) Many veterinarians recommend vitamin C for dogs who are prone to
bladder infections and struvite stones because of its anti-inflammatory
effects. Dogs (unlike humans) manufacture their own vitamin C, but the amount
they produce may not meet their needs if they are under stress or fighting
infection.
The ascorbate
form of vitamin C is most often recommended for dogs, as it may be better
absorbed and is less prone to causing gastrointestinal upset. Calcium ascorbate
and sodium ascorbate are available in generic forms as a powder, but the most
popular form is a product called Ester-C, which contains calcium ascorbate and
vitamin C metabolites.
Veterinary
recommendations range from 250 mg twice per day for every 15 to 30 pounds of
body weight up to a maximum of 1,000 mg twice a day for large dogs. Because
vitamin C can cause diarrhea, start with small doses and increase gradually.
The maximum amount your dog can tolerate without the diarrhea side effect is
called her “bowel tolerance”dose.
The herb
uva ursi (Arctostaphylos uva-ursi) is used in many herbal blends for bladder
infections because of its antibacterial properties. Uva ursi is best used for
short periods rather than for months at a time as it can irritate the kidneys.
The dosage for this herb depends on the individual blend and how it was
prepared. Follow label directions for products formulated for dogs; adjust the
dosage of products meant for humans by weight, assuming the human’s weight at
100 to 120 pounds.
While
adding salt to your dog’s food is an effective way to encourage drinking more
fluids for dogs who don’t tend to drink enough, consider switching from refined
table salt to unrefined sea salt, which is sold in natural food markets and
contains dozens of minerals and trace elements that are not present in refined
salt.
Since
most homemade diets are low in salt compared to commercial foods, the amount of
salt to add will depend on the diet you feed. Start by adding a pinch of salt
(small for a small dog, larger for a large dog) to your dog’s food and watch to
see if it makes her more thirsty. Increase the amount by a pinch at a time
until she is drinking more than usual.
Traditional
broth or stock is easy to make at home by simmering chicken, beef, or other
bones in water overnight or for 24 to 36 hours. If desired, add carrots and
other vegetables. Replace evaporating water as needed. The longer the simmer,
the more nutritionally dense the broth and the more interesting it is likely to
be to your dog. Broth can be used as a flavor enhancer when strained and added
to food or given in addition to water. Be sure to provide plain drinking water
at all times.
Struvite
stones can make any dog miserable, but by understanding how and why they occur
and by taking the preventive measures described here, you can be sure that your
dog lives a happy, stone-free life.
Next
month: Calcium
oxalate uroliths, America’s most common canine urinary stones.
CJ
Puotinen is the
author of The Encyclopedia of Natural Pet Care and other holistic health books.
She lives in Montana, and is a frequent contributor to WDJ.
San Francisco
Bay Area resident Mary Straus has spent more than a decade investigating and
writing about canine health and nutrition topics for her website, DogAware.com
northernwitch-
- Number of posts : 11031
Location : Toronto, Ontario -
Re: Crystals and malformed kidneys
Aussie Witch 1/20/2012, 8:39 pm
Blanche has given some great info, so I will just add my good thoughts that you can get things under control. Please keep us updated.
Aussie Witch-
- Number of posts : 8556
Location : The Antipodes.
Thank you so much!
Willowsmom 1/21/2012, 12:25 pm
Just a SUPER big Thank You!! I now have some info to set up some type of care/defense. I don't feel bad about vet 2. He is just a stumped as I was. As I wrote, he was given a range of all sorts of opinions. He was told by other professionals, there wasn't enough data to reference to, because most owners would opt to put their dog down. As I told him, that is not an option at this point. As long as she is doing good, I will do whatever I can to give her a good quality of life. I adopted her in August 2011, from the Humane association and she apparently had this then. Now that I know there is something I can do, I feel so much better. You will never know how much I appreciate you all and this site. Again, from deep in my heart and through the tears (they are happy ones now ) Thank you. Kat
Willowsmom-
- Number of posts : 8
Location : ohio
Re: Crystals and malformed kidneys
Pugsaunt 1/21/2012, 6:15 pm
And this is yet another reason why I love PA and the wonderful people here.
Pugsaunt-
- Number of posts : 6877
Location : On the shores of Penny's Marina in Sparks, NV
Re: Crystals and malformed kidneys
northernwitch 1/22/2012, 8:34 pm
Kat:
The Whole Dog Journal did a whole three issue feature on uroliths (urinary stones and crystals). I will say that they can be the devil to get rid of especially in an older dog that has a history of them. And if she gets infections, get the vet to do a Culture and Sensitivity test so you can be sure that the antibiotic she's on is the RIGHT one for the infection--too many vets just slam a dog with antibiotics without ensuring it's effective and it really sets up a bad road to resistant infections.
I have found over the years that the key to these kinds of dogs is LOTS of fluids and lots of opportunities to pee. The more she can flush out that system, the better. They should never be in a position to hold their bladders if it can be avoided. It's one of the reasons that I really discourage people from making their dogs, small ones especially, hold their bladders all day while owners are at work. It's terrible for the bladder. And dreadful for dogs with bladder/kidney issues.
The Whole Dog Journal did a whole three issue feature on uroliths (urinary stones and crystals). I will say that they can be the devil to get rid of especially in an older dog that has a history of them. And if she gets infections, get the vet to do a Culture and Sensitivity test so you can be sure that the antibiotic she's on is the RIGHT one for the infection--too many vets just slam a dog with antibiotics without ensuring it's effective and it really sets up a bad road to resistant infections.
I have found over the years that the key to these kinds of dogs is LOTS of fluids and lots of opportunities to pee. The more she can flush out that system, the better. They should never be in a position to hold their bladders if it can be avoided. It's one of the reasons that I really discourage people from making their dogs, small ones especially, hold their bladders all day while owners are at work. It's terrible for the bladder. And dreadful for dogs with bladder/kidney issues.
northernwitch-
- Number of posts : 11031
Location : Toronto, Ontario -
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