http://thebark.com/content/dna-test-helps-dalmatians
link to article about hyperuicosuria disease dna testing
How do you acknowledge a Dalmatian? If “youre thinking about” the movie 101 Dalmatians or the dog who traditionally rides on the fire engine, it’s easy. Dalmatians are, of course, known for their characteristic places — breeders have spent many years selecting for puppies with spotting patterns that fit the ideal spawned standard: evenly distributed, distinct, well-defined round places that are larger than a dime but smaller than a half dollar. However, sometimes the bad unexpectedly comes along with the very best. Breeding for these patterns has brought with it a predisposition to sort bladder stones, a condition that is potentially life threatening. Now, with the help of a special group of Dalmatians and some dedicated breeders, scientists have unearthed the cause of this circumstance and designed a DNA test that will not only improve Dalmatian health, but will benefit other puppies as well.
In most puppies, the proteins in food broken up in the liver, and the byproduct, allantoin, is excreted by the kidneys into the urine, where it dissolves. In Dalmatians, the process stops at the step before the production of allantoin; instead, uric acid is made. Because uric acid does not dissolve well in urine, it can sort urate stones in the bladder, and these stones can block the urethra; in serious cases, this circumstance involves surgery to resolve. The accumulation of high levels of uric acid in the urine is called hyperuricosuria( huu ).
Huu, which was first described in 1916, was shown in 1938 to have a recessive mode of inheritance( an individual must have two copies of the mutation to be affected ). All Dalmatians carry two copies of the huu mutant, means that within the purebred Dalmatian population, there is no way to breed puppies with low levels of uric acid because the trait does not exist in their gene pool. Consequently, Dalmatians render 20 times more uric acids per day than other puppies and are prone to urate stones.( Interestingly, although all Dalmatians have high levels of uric acid , not all exhibit clinical illnes. The reason for this is unknown .)
In order to correct this condition, a normal, low-uric-acid copy of the gene had to be introduced into the gene pool. In 1973, Dr. Robert Schaible, a medical geneticist and Dalmatian breeder, bred a Dalmatian to a Pointer and then bred the offspring back to purebred Dalmatians. The goal of this backcross was to produce puppies who looked and acted like Dalmatians, but who had normal( i.e ., low) uric acid levels in their urine and therefore would not render bladder stones. Each time one of these backcross Dalmatians( with low levels of uric acid, or LUA puppies) is bred to a purebred Dalmatian( with high levels of uric acid, or HUA puppies ), about 50 percentage of the puppies are LUA and 50 percentage are HUA.
LUA puppies tend to have smaller places than HUA puppies, _empty_ further evidence that the huu mutant was unintentionally selected for along with the deliberate selection for place patterns. Although the places on LUA puppies are generally smaller, they still fall within the guidelines of the Dalmatian standard as outlined by the American Kennel Club( AKC ).
Two backcross Dalmatian puppies from the fifth generation were registered with the AKC, which meant that they could be shown in AKC-recognized events. The registration was later resisted, and farther registration of backcross puppies was prohibited. The issue of AKC backcross Dalmatian registration continues to be controversial and emotional. Backcross Dalmatians can be registered with the United Kennel Club.
Since most serious breeders register their puppies with the AKC, the number of purebred Dalmatians available to backcross breeders became severely limited because the puppies were not eligible for AKC registration. By 2005, after 30 years of run, few breeders were using backcross puppies in their programs, and Dr. Schaible was limited by the number of puppies he could keep himself, factors that suggested the project was nearing an aim. Around that time, Denise Powell, a northern California Dalmatian breeder for more than 20 years, contacted Dr. Schaible to inquire about spawning backcross Dalmatians.” I was shocked to learn that he had just two aging stud puppies and two newborn female pups ,” says Powell.” I chose then and there to do what I could to help preserve the only line of LUA Dalmatians in the world from dying out. I asked, and Bob agreed to let me have one of the two pups .”
How do you recognise a Dalmatian? If” youre thinking about” the movie 101 Dalmatians or the dog who traditionally rides on the fire engine, it’s easy. Dalmatians are, of course, known for their characteristic places — breeders have expended many years selecting for puppies with spotting patterns that fit the ideal breed criterion: evenly distributed, distinct, well-defined round places that are larger than a dime but smaller than a half dollar. However, sometimes the bad accidentally comes along with the very best. Spawning for these patterns has brought with it a predisposition to sort bladder stones, a condition that is potentially life threatening. Now, with the help of a special group of Dalmatians and some dedicated breeders, scientists have unearthed the cause of this condition and designed a Dna exam that will not only improve Dalmatian health, but will benefit other puppies as well.
In most puppies, the proteins in food are broken down in the liver, and the byproduct, allantoin, is excreted by the kidneys into the urine, where it dissolves. In Dalmatians, the process stops at the step before the production of allantoin; instead, uric acid is made. Because uric acid does not dissolve well in urine, it can sort urate stones in the bladder, and these stones can block the urethra; in serious cases, this condition involves surgery to resolve. The accumulation of high levels of uric acid in the urine is called hyperuricosuria( huu ).
Huu, which was first described in 1916, was shown in 1938 to have a recessive mode of inheritance( an individual must have two copies of the mutation to be affected ). All Dalmatians carry two copies of the huu mutant, means that within the purebred Dalmatian population, there is no way to spawn puppies with low levels of uric acid because the trait does not exist in their gene pond. Consequently, Dalmatians construct 20 times more uric acid per day than other puppies and are prone to urate stones .( Interestingly, although all Dalmatians have high levels of uric acid , not all exhibit clinical illnes. The reason for this is unknown .)
In order to correct this condition, a normal, low-uric-acid transcript of the gene had to be introduced into the gene pond. In 1973, Dr. Robert Schaible, a medical geneticist and Dalmatian breeder, spawned a Dalmatian to a Pointer and then spawned the offspring back to purebred Dalmatians. The objective of this backcross was to produce puppies who appeared and acted like Dalmatians, but who had normal( i.e ., high) uric acid levels in their urine and therefore would not construct bladder stones. Each day one of these backcross Dalmatians( with low levels of uric acid, or LUA puppies) is spawned to a purebred Dalmatian( with high levels of uric acid, or HUA puppies ), about 50 percent of the puppies are LUA and 50 percent are HUA.
LUA puppies tend to have smaller places than HUA puppies, further proof that the huu mutant was unintentionally selected for along with the deliberate selection for place patterns. Although the places on LUA puppies are generally smaller, they are continuing fall within the guidelines of the Dalmatian criterion as outlined by the American Kennel Club( AKC ).
Two backcross Dalmatian puppies from the fifth generation were registered with the AKC, which meant that they could be shown in AKC-recognized events. The enrollment was subsequently eluded, and further enrollment of backcross puppies was proscribed. The issue of AKC backcross Dalmatian registration continues to be controversial and emotional. Backcross Dalmatians can be registered with the United Kennel Club.
Since most serious breeders register their puppies with the AKC, the number of purebred Dalmatians available to backcross breeders became extremely few because the puppies were not eligible for AKC registration. By 2005, after 30 years of operate, few breeders were use backcross puppies in their programs, and Dr. Schaible was limited by the number of puppies he could maintain himself, factors that suggested the project was nearing the following objectives. Around that time, Denise Powell, a northern California Dalmatian breeder for more than 20 years, contacted Dr. Schaible to inquire about spawning backcross Dalmatians .” I was shocked to learn that he had just two aging stud puppies and two infant female puppies ,” says Powell .” I preferred then and there to do what I could to help preserve the only line of LUA Dalmatians in the world from succumbing out. I asked, and Bob agreed to let me have one of the two puppies .”
How do you recognise a Dalmatian? If” youre thinking about” the movie 101 Dalmatians or the dog who traditionally rides on the fire engine, it’s easy. Dalmatians are, of course, known for their characteristic places — breeders have expended many years selecting for puppies with spotting patterns that fit the ideal breed criterion: evenly distributed, distinct, well-defined round places that are larger than a dime but smaller than a half dollar. However, sometimes the bad accidentally comes along with the very best. Spawning for these patterns has brought with it a predisposition to sort bladder stones, a condition that is potentially life threatening. Now, with the help of a special group of Dalmatians and some dedicated breeders, scientists have unearthed the cause of this condition and designed a Dna exam that will not only improve Dalmatian health, but will benefit other puppies as well.
In most puppies, the proteins in food are broken down in the liver, and the byproduct, allantoin, is excreted by the kidneys into the urine, where it dissolves. In Dalmatians, the process stops at the step before the production of allantoin; instead, uric acid is made. Because uric acid does not dissolve well in urine, it can sort urate stones in the bladder, and these stones can block the urethra; in serious cases, this condition involves surgery to resolve. The accumulation of high levels of uric acid in the urine is called hyperuricosuria( huu ).
Huu, which was first described in 1916, was shown in 1938 to have a recessive mode of inheritance( an individual must have two copies of the mutation to be affected ). All Dalmatians carry two copies of the huu mutant, means that within the purebred Dalmatian population, there is no way to spawn puppies with low levels of uric acid because the trait does not exist in their gene pond. Consequently, Dalmatians construct 20 times more uric acid per day than other puppies and are prone to urate stones .( Interestingly, although all Dalmatians have high levels of uric acid , not all exhibit clinical illnes. The reason for this is unknown .)
In order to correct this condition, a normal, low-uric-acid transcript of the gene had to be introduced into the gene pond. In 1973, Dr. Robert Schaible, a medical geneticist and Dalmatian breeder, spawned a Dalmatian to a Pointer and then spawned the offspring back to purebred Dalmatians. The objective of this backcross was to produce puppies who appeared and acted like Dalmatians, but who had normal( i.e ., high) uric acid levels in their urine and therefore would not construct bladder stones. Each day one of these backcross Dalmatians( with low levels of uric acid, or LUA puppies) is spawned to a purebred Dalmatian( with high levels of uric acid, or HUA puppies ), about 50 percent of the puppies are LUA and 50 percent are HUA.
LUA puppies tend to have smaller places than HUA puppies, further proof that the huu mutant was unintentionally selected for along with the deliberate selection for place patterns. Although the places on LUA puppies are generally smaller, they are continuing fall within the guidelines of the Dalmatian criterion as outlined by the American Kennel Club( AKC ).
Two backcross Dalmatian puppies from the fifth generation were registered with the AKC, which meant that they could be shown in AKC-recognized events. The enrollment was subsequently eluded, and further enrollment of backcross puppies was proscribed. The issue of AKC backcross Dalmatian registration continues to be controversial and emotional. Backcross Dalmatians can be registered with the United Kennel Club.
Since most serious breeders register their puppies with the AKC, the number of purebred Dalmatians available to backcross breeders became extremely few because the puppies were not eligible for AKC registration. By 2005, after 30 years of operate, few breeders were use backcross puppies in their programs, and Dr. Schaible was limited by the number of puppies he could maintain himself, factors that suggested the project was nearing the following objectives. Around that time, Denise Powell, a northern California Dalmatian breeder for more than 20 years, contacted Dr. Schaible to inquire about spawning backcross Dalmatians .” I was shocked to learn that he had just two aging stud puppies and two infant female puppies ,” says Powell .” I preferred then and there to do what I could to help preserve the only line of LUA Dalmatians in the world from succumbing out. I asked, and Bob agreed to let me have one of the two puppies .”
Not spun below
Powell’s dedication led to the creation of the Dalmatian Heritage Project, which in turn sparked the involvement of other Dalmatian breeders and the expansion of the backcross population. Current descendants of the original cross represent the 12th generation of the family. There is only one Pointer out of more than 4,000 relatives in the pedigrees of the backcross dogs, which makes them more than 99 percent Dalmatian.
Backcross dogs undergo all the health screenings recommended for AKCregistered Dalmatians, including Brainstem Auditory Evoked Response (BAER) hearing testing, temperament analysis, conformational analysis and, in some cases, Orthopedic Foundation for Animals (OFA) hip exams and Canine Eye Registration Foundation (CERF) eye evaluations.
Danika L. Bannasch, DVM, PhD, associate professor of genetics at the University of California, Davis, School of Veterinary Medicine—and Dalmatian owner and former breeder—became involved with the project in 1998. Using blood samples and pedigree information from generations of backcross Dalmatians, Dr. Bannasch and her colleagues recently identified a mutation in the SLC2A9 gene that causes huu in Dalmatians. The mutation correlates perfectly with a dog’s huu status: Only HUA dogs have two copies of the mutation. “The biggest challenge to finding the genetic cause for huu in Dalmatians was the fact that the trait is fixed in the breed,” says Bannasch.“If we didn’t have the backcross, it would have been impossible to do.”
The scientific data reporting the identification of the huu mutation has been published in the peer-reviewed genetics journal of the Public Library of Science (PLoS), and a DNA test for the mutation is now available through the Veterinary Genetics Laboratory at UC Davis. Previously, a laborious and expensive urine test was required to determine whether a dog was LUA or HUA. The DNA test eliminates the need for the urine test and makes selection easier in the backcross Dalmatians.
The positive impact of this genetic discovery extends beyond Dalmatians. High levels of uric acid and urate stone formation have been reported in individuals from other breeds, including Bulldogs and Black Russian Terriers. Testing in Dr. Bannasch’s laboratory has confirmed that the mutation responsible for huu in these breeds is the same one identified in Dalmatians.
“Now we have a means for identifying the probable major cause for urate disease in dogs,”says Bannasch.“If you know your dog is predisposed to form bladder stones, you can alter things about their management and be aware of the signs of stone disease.”
The huu mystery described in Dalmatians more than 90 years ago has been solved through visionary thinking and tireless dedication. Advances in genetics enabled the creation of a DNA test that will benefit not only Dalmatians, but other dogs as well. The story of the backcross Dalmatians exemplifies the profound impact on canine health that breeders, owners, veterinarians and scientists can achieve by working together.