DALMATIANS URINARY STONE DISEASE:
A COMPENDIUM OF SCIENTIFIC INFORMATION
Carroll H. Weiss
Former Director (1991-2002)
Study Group on Urinary Stones
Dalmatian Club of America
(Last update: March 2007)
Since 1938, Dalmatians are the only breed of dogs known by veterinarians to be born with a defect
in how they produce their urine resulting in some of the breed forming insoluble "urates," one of
several types of urinary stones. Only two other living species share the defect - humans and apes.
Not every human forms urinary stones (or gout, its alternative) and neither will every Dalmatian.
The breed-specific defect takes place during production of urine within the breed’s liver and
kidneys so that one waste chemical - “uric acid” - soluble in other dog breeds is insoluble in
Dalmatian urine. It thereby precipitates out as abnormal urinary crystals or abnormal urinary
stones in particular those made up of “urates” which are forms of uric acid. Crystals are young,
immature stones and, undiagnosed or untreated, usually enlarge to become full-size adult stones.
This compendium of information is directed to preventing your Dalmatian’s urinary flow
being blocked by a large enough stone to create the ominous “urinary obstruction”
when urine - dammed up and unable to be expelled - backs up into the dog’s system
and thereby becomes life-threatening within 24 to 72 hours.
Happily, there now are decades of advanced veterinary experience with the breed-specific urates
urinary stones. Of those, one specific urate occurs in up to 96 percent of stone-forming
Dalmatians: ”ammonium acid urate.” Unlike some other urinary stones, ammonium acid urate is
especially responsive to knowledgeable non-surgical treatment and when the stone-forming
Dalmatian is stabilized, an equally successful yet simple program of prevention.
Despite the vast majority of afflicted Dalmatians confirmed with urate stone disease, there are
different and other prevalent t