The Low Uric Acid Backcross Project

Many breeders believe that there was a genetic mutation that caused for the spots of Dalmatians to become bolder and more appealing to the eye back in the mid 1900’s. When this took place, breeders continued to breed to this line as they thought that they were improving the breed and its spotting pattern.  There was also a mutation that changed the uric acid metabolism that made it harder for these Dalmatians to process purines.  The mutation for this new and attractive spotting is on the same loci as the gene that causes the high uric acid (HUA).  HUA Dalmatians are prone to uric acid crystals in the bladder. When breeding to this line of Dalmatians with attractive spotting, the breeders were unknowingly introducing the mutation for urate stones into the breed as well.  

If these crystals are not evacuated by flushing out the bladder with large drinks of water, the crystals can build up and turn to stones.  If a stone(s) gets caught in the urethra of the dog, he/she will not be able to urinate and will need to be taken to a veterinarian.  Although there can be several approaches to solve this issue, the most common way is to perform a surgery that will remove the stone(s).  This surgery comes along with about a six-week recovery time, depending on the dog itself.  Males are more susceptible to block with a urate stone than females, because of their anatomy.  They have a long and narrow urethra can cause a small stone to get stuck much more easily than a female’s urethra that is shorter and wider. 

Back in 1940 Keeler, who was a researcher could not find a Dalmatian with normal uric acid in the United Kingdom or in the United States of America to breed to.  After much research, Robert Schaible Ph. D., who was a long time Dalmatian breeder, began to think of ways to reintroduce the gene that eliminates uric acid stones, which is known as the hyperuricosuria (SCL2A9) or more commonly known as the Low Uric Acid (LUA) gene, back into the gene pool.  He bred a Dalmatian to a Collie in hopes that he could start his backcross project.  He was also researching other breeds that could have been incorporated into the breed as well.  In 1973, he bred a champion Pointer to a Dalmatian.  This was the best way to reintroduce this good LUA gene back into the Dalmatian breed.  This outcross only happened one time.  He had started a new line of LUA Dalmatians that were not able to produce uric acid stones.  Since that outcross breeding (Pointer – Dalmatian) there have only ever been Dalmatians bred into this line.  Practices like this were common in the American Kennel Club to introduce a trait or gene into a breed that would improve it, back before the 1900’s.  Back then, after three generations were passed, the decedents were able to be registered and compete in the conformation and performance rings.  Sadly, this practice was not accepted when the Backcross Project stared.  The United Kennel Club (UKC) approved this line and had a club that was all pro LUA.  Dalmatians of North America (DNA) was filled with great representations of the breed that also had healthy bladders.   LUA Dalmatians were accepted by the American Kennel Club in 2011 after a long debate on whether or not these dogs, that were now 99.999% Dalmatian, were considered pure bred or not.  

Stocklore Hybrid (First Generation LUA Dalmatian)

(Pointer – Dalmatian Pedigree)

As Robert Schaible Ph. D. continued his project, he earned the support of fellow breeders who believed in his work.  At the same time, a lot of people resented the idea and called his dogs “mutts.”   While these dogs are decedents of two different breeds that were brought together to fix a health problem that has affecetd the breed in its entirety, there are many breeds that were created the exact same way, such as the Doberman Pincher.  As more people learned about the backcross project, more breeders introduced this line of Dalmatian into their kennel, and suddenly there were LUA Dalmatians all over the United States.  Breeders have been able to widen the gene pool so much that the project is now worldwide.  Semen was shipped to many different countries from different dogs to allow for them to introduce this good LUA gene into their lines as well. 

Some breeders began to breed LUA Dalmatians to other LUA Dalmatians to increase the chances of producing more dogs with healthy bladders.  Since the LUA Gene is dominant, the dog only needs to have one copy of it to be protected from urate stones and crystals.  If the dog has two copies, that means that all of his/her offspring will have at least one copy as well, and none of them will be able to produce urate stones.  When breeders talk about the LUA gene specifically, it is represented as N/N (Homozygous LUA), N/hu (Heterozygous LUA), or hu/hu (Homozygous HUA).  

Below is a punnent square.  To find out the probability of having LUA Dalmatians within one litter, follow one parent’s genotype and connect it to the other parent’s genotype.