August 12, 2015
Well if you don’t know that “Spotty” is the perfect name for a Dalmation dog then you’re not a kid. Clarity is not reserved to children, but I find they are less likely to obfuscate descriptive terms. And a Dalmatian dog, though born white, is soon covered with a myriad of black (or brown) spots. This breed has been beloved for centuries, serving as a watch dog, a fire station dog and starring in a famous Disney movie. Going back to their origins, they were selected for their beautiful coats and rugged nature to accompany coaches, travelling long distances as guards. This led to them serving horse-drawn fire wagons, as they could keep up with the horses, barking an alert to clear people out of the way. At the scene of the fire they both calmed the horses and guarded the wagon. One tough, sturdy breed of dog. Despite the movie (all puppies are cute), Dalmatians are a breed highly unsuitable to be penned up in a house with little to do. No action hero likes to be sidelined. But the Dalmation mania has subsided and these days we see dogs well suited to their homes. Some even belong to firefighters!
Spotty was a family pet. He had recently celebrated his fifth birthday. He looked forward to his daily bowl of kibble and walk in the park. But….something seemed a little off. Spotty passed on his kibble one night and at the park he seemed to strain to urinate. In fact, he’d walk a few paces and lift his leg, but nothing came out. By the next morning Spotty wasn’t walking very well. His hind legs seemed stiff and he was panting and anxious. Sometimes his stomach would heave and it was hard to tell if he was trying to vomit or urinate but nothing came out either end. Spotty seemed painful. Time to go to the vet.
In the hospital it was obvious Spotty was in distress from a distance. Panting and unwilling to walk, the reason was soon obvious. His abdomen was mildly distended and palpation identified a very large, firm bladder. It hurt to touch and Spotty was in no mood to be brave. We had a strong suspicion as to the cause of Spotty’s problem.
You see, the Dalmatian breed of dog has a unique inherited predisposition to uric acid bladder stones. Foods like organ meat or seafood are high in a form of protein called purines. The liver is supposed to break this protein down into a harmless substance that the body absorbs but in Dalmatians, lacking this gene, the liver only processes the protein into uric acid, which is filtered through the kidneys and settles out as small stones (as hard as coarse sand) into the bladder. The best way I can draw this picture with words is to compare the Dalmatian, a mammal, to birds. Birds are uricotelic, meaning they do not break down body waste into urine but instead their kidneys excrete uric acid, the solid white matter you see in a bird dropping. This is normal for a bird. But mammals – dogs – are supposed to excrete waste filtered through the kidneys as a thin fluid, urine. Dalmatian dogs make urine, but some will also make uric acid crystals which build up in the kidneys and bladder. Hundreds of these crystals can be deposited inside the bladder and obstruct the male Dalmatian dog’s ability to urinate. Once the bladder outlet is obstructed the dog can’t urinate and the bladder will slowly fill as the kidneys continue to produce both urine and uric acid. Without relief of the obstruction the bladder will rupture and/or the kidneys shut down, both potentially leading to death.
Spotty’s abdominal x-ray showed an enormous bladder, though the uric acid stones causing the problem weren’t well defined. His bloodwork demonstrated kidney distress, but within parameters that we felt could be reversed to normal once his obstruction was surgically cleared. We whisked Spotty in for emergency surgery, relieving his obstruction and emptying his bladder of hundreds of tiny grey stones. Intravenous fluids helped get his kidneys up and running again, a process we call diuresis. The stones or uroliths were analyzed to be certain they were uric acid in nature and a proper prevention plan put in place.
We know that high protein, meat-based diets may not be the best choice for any Dalmatian at this time as many are formulated with high purine foods of organ meat or seafood. Avoiding these purine-rich foods puts less burden on the liver and can greatly decrease the formation of stones. Dietary avoidance of these foods is a cornerstone to prevention.
This condition is similar to the disease of gout in people. In people the uric acid crystals settle in the joints, causing inflammation and pain. Interestingly, the same medication may be used to treat both humans and canines.
Spotty is lucky. Through a low-protein, non-meat based diet, medication and monitoring of his urine he is expected to lead a full, normal life. Because the gene has been identified, Dalmatian breeders can now specifically test and work to breed out this genetic mutation. The Veterinary Genetics Lab at the University of California, Davis, School of Veterinary Medicine offers genetic testing for a variety of breed-inherited diseases.
Christine B. McFadden, DVM
drmc@mcmenagerie.com