The Dalmatian Club of America
DCA Teaching Seminar by Joseph Bartges, DVM, PhD
1992 Dalmatian Club of America's Annual Educational
August 10th in Reading, Pennsylvania:
JOSEPH W. BARTGES, DVM
Minnesota Urolith Center
University of Minnesota
School of Veterinary Medicine
St. Paul, Minnesota
(see current affiliation at end of this abstract)
The following summary is just the
"tip of the iceberg" from his thoroughly complete up-to-the-minute status
of urinary stone-forming in dogs including Dalmatians.
Obstruction of urine flow by stones or by other causes,
left untreated, is an emergency situation and can quickly become a life-threatening
condition. The most desirable goals when confronted with a stone-forming
Dalmatian is to relieve and remove the obstruction if present, either dissolve
the stones or remove them by surgery and to put the Dal then on a preventative
treatment program to minimize further stone-forming problems. In order
to do this, some concepts of urinary crystals and stones must be understood.
The vast majority of canine stones, including those occurring
in Dalmatians, are found in the lower urinary system (bladder, urethra).
Unlike other breeds, the liver and kidney of Dalmatians appear to process
certain substances called "purines" in a unique fashion, setting the stage
for possible crystal and stone formation in the urine. In some Dalmatians,
this defect and their diet cumulatively result in what is termed "unstable
urine." Unstable urine occurs when many factors exist including but not
limited to: abnormal pH of the urine, super-saturation of the urine, presence
in the urine of crystal-forming compounds, abnormal urinary temperature,
Crystals and stones will form in supersaturated urine
and should be identified as to their mineral content to determine specific
preventative protocols which are different mineral-to-mineral. Of 11,269
stones (all breeds) sent to the Minnesota Urolith Center for assay, the
predominate mineral was struvite, followed by calcium oxalate and purines
which include urates (uric acid or sodium urate or ammonium acid urate).
The most common Dalmatian stones were urates and, of those, the most common
form was ammonium acid urate.
Urinary infections can cause stone formation, most frequently
struvite stones, when the pH generally is alkaline (above 7.0). Two to
three percent of all dogs develop urinary infections, and the three bacterial
species most commonly causing them are E. coli, Staphylococcus and
Of the three species, E. coli is found most often but does
not predispose to stone formation. However, urinary infections with Staph.
or Proteus are stone-forming when Dr. Bartges cited the urinary
pH can alkalinize up to 7.8 or 7.9.
Urinary infections do not create urate stones (the most
common Dalmatian ones) but conversely URATE STONES ONCE PRESENT CAN
CAUSE "SECONDARY" URINARY INFECTIONS where none existed before and
the infection, in turn, can then complicate the diagnosis.
Non-surgical treatment of stone-forming Dalmatians involves:
If the Dalmatian's urine flow is blocked by stones and the
bladder has not been able to be emptied but instead has filled to the point
of causing pressure and pain by being dammed up, Dr. Bartges recommended
"urinary cystocentesis" whereby a needle is inserted through the abdomen
into the bladder and the urine is withdrawn by a syringe. This tapping
of urine from within the bladder "buys time" while the dog's condition
is evaluated and attempts to succeed with non-surgical treatment proceed.
Some small stones can be flushed out by use of a catheter whose end has
been cut and smoothed. A final method of immediately reopening the urine
flow is "urinary hydropropulsion" whereby saline is forced under pressure
through a catheter into the urinary pathway and the fluid back-flushes
the stones up into the bladder. The hydropropulsion may have to be repeated
more than once and most dogs tolerate the procedure well, Dr. Bartges added.
locating the site of stones and their number by direct or
indirect x-ray or ultrasound. (Urate stones, the most common in Dalmatians,
do not show up under standard x-rays. Their visualization requires other
x-ray techniques or ultrasound),
removal of existing stones from where they are blocking urine
identifying their mineral content,
antibiotics for prevention or treatment of urinary infection,
anti-stone-forming diet, and
Assay of the crystal or stone mineral content, he explained,
can be done by two methods: qualitative and quantitative. Qualitative assay
has been shown to have as many as 60 percent errors and additionally does
not identify xanthine, one of the purines which can form Dalmatian stones.
Dr. Bartges urges assay of crystals or stones only by quantitative methods.
His Minnesota Urolith Center does not charge for this type of identification.
For Dalmatians whose crystals or stones have been assayed
to be purines and in particular ammonium acid urate (the most common Dalmatian
one),a preventative program can be started including:
Dr. Bartges noted that current food labeling does not list
which ingredients are high in purines but in general, "HIGH PROTEIN"
FOODS SUCH AS MEAT AND BEEF CONTAIN A GREAT DEAL OF PURINES and are
foods to be avoided for purine stone-forming dogs like Dalmatians and Bulldogs.
Hill's u/d, a milk protein-based prescription diet which
has been shown to be effective against urate stone-forming,
the drug, allopurinol, which is effective in dissolving of
urate stones, and
changing the acidic urine associated with urate stone-forming
by giving the Dal an alkalinizing agent like potassium citrate although,
Dr. Bartges added, the u/d diet alone should suffice to alkalinize the
Dr. Bartges cautioned that recent studies have shown the
amount of dosage of the drug allopurinol should be carefully prescribed
because it can paradoxically cause the formation of xanthine, another purine
stone. This side effect has been prevalent when allopurinol is given to
dogs also receiving a high protein diet but is much less frequent when
the diet is low in protein and, in particular, low in those proteins containing
purines. When allopurinol is given the same time as the antibiotic, Ampicillin,
another side effect of drug treatment may be dermatitis. Dr. Bartges concluded
by emphasizing that if the stones causing urine blockage can be removed
by passing or by catheterization or by hydropropulsion, bladder surgery
can be avoided in many instances. If non-surgical treatment is successful,
stones maybe passed or dissolved within an average of three months. If
stones are still creating problems after that time, one or all of four
explanations may explain the disappointing results:
The most important key to successful non-surgical
treatment of urinary stones, Dr. Bartges stressed, is frequent, periodic
monitoring of the stone-forming Dalmatian.
the wrong mineral was identified and accordingly the wrong
treatment to dissolve stones containing it was used,
the original mineral content was correct but subsequently
other and different minerals were created,
stone-forming drugs were given,
either or both owner and dog were not strictly and conscientiously
following the treatment procedures.
Dr. JosephBartges, DVM, Ph.D.
now is located at:
Dept. of Small Animal Clinical Sciences
U. Tennessee Veterinary College
P.O. Box 1071
Knoxville TN 37901-1071
Phone: (423) 974-8387
Fax: (423) 974-5554
Study Group on Urinary Stones
Dalmatian Club of America
Tracie Tepke, Director
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