Most Dalmatian health surveys, veterinarian reports and research studies show that uric acid related stone disease is a problem in the Dalmatian as a Breed, and that this problem is fairly common.  Different studies get different results, but overall it is thought that somewhere between fewer than 10% to as many as 30% of Dalmatians may develop stone disease during their lifetime.  The exact number is a point of debate amongst breeders, vets and scientists.  It is almost impossible to get a definitive answer and probably cannot ever be known.
In normal dogs, proteins in food (specifically purine proteins) are broken down by the metabolic machinery in the liver to an end product called allantoin.  Allantoin is excreted into the urine by the kidney, and is soluble in the urine in the bladder (i.e., does not form crystals or stones).  In the Dalmatian, the metabolism of purine proteins stops at one step earlier - at uric acid.  Although the Dalmatian has the normal enzyme called uricase to metabolize uric acid to allantoin, the uric acid just cannot get to the cell for the uricase to work on because there is a missing transporter protein that is responsible for doing that.  So instead, uric acid is excreted into the urine by the kidney.

Uric acid is less soluble than allantoin, and under certain concentrations and pH conditions, uric acid can come out of solution as a salt called urate.  Urates can form crystals, which can clump together to form aggregates, and even bigger pieces - stones.  Stones can form of various sizes, and if large enough, stones can block the urethra - the tube leading from the bladder to the outside world of the Dalmatian and onto your carpet or the grass.  This blockage is much more common in male Dalmatians than females because the males have something called the os penis - a bone in their penis that is very small in caliber and can easily become blocked.

There are some environmental risk factors that increase the likelihood that urinary uric acid will form solids (stones) in the bladder, such as inadequate water intake, or if urine stays in the bladder for an extended period of time.  Diets particularly rich in proteins, and specifically high in purine content (like feeding or baiting with liver) can increase the risk of increasing urinary uric acid.  Sometimes local water properties can exacerbate the problem.  Breeders and owners must manage the percentage of protein in the food that is provided to their Dalmatian - generally around 21% - and be cautious that the formula is relatively low in purine proteins - no liver.  Adequate and liberal access to water is important, as are frequent opportunities to exercise and relieve the Dalmatian.

Although the precise causative factor for the formation of uric acid stones may not be known for a given Dalmatian, it is clear that several factors may be contributory, such as diet, water access, exercise, possibly stress, and others.  A common feature though is the high level of uric acid in the urine of the Dalmatian, which has been reported to be from 400 to 800 mg/dl.  This is 10 to 20 times higher than the normal canine level of about 40 mg/dl.

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