LUA / NUA Dalmatians
At Tippledal we have chosen to breed using LUA dalmatians. We believe in breeding for the whole dog and trying to improve each generation. This means breeding for a whole range of factors; temperament, good hearing background (breeding only from bilaterally hearing parents), history of good hip and elbow scores, construction and movement are all important aspects so adding LUA to that can only better the breed right? Here is a little about LUA dalmatians.
The problem? Hyperuricosuria - Bladder Stones
All Dalmatians, except for those originating from the LUA Dalmatian back cross project, have two copies of a recessive mutant gene (hu/hu), which means they are unable to process uric acid correctly. This results in abnormally high levels of uric acid in their urine and a predisposition to form urate stones in the bladder and sometimes the kidneys; this can cause urinary obstruction (a potentially fatal medical emergency).
The improvement? The LUA gene
LUA dalmatians possess at least one copy of the non-mutated, correct gene (heterozygous N/hu or homozygous N/N) which allows them to process uric acid correctly.
HUA dals have 2 copies of the defective gene and cannot properly metabolise purines. LUA dals have one or two copies of the wild (normal) gene that permits proper purine metabolism. The wild gene is dominant, so even with only one gene, the dog can properly metabolise purines.
How was this gene incorporated into the breed? The Dalmatian Backcross Project & 'LUA' or 'NUA' Dalmatians
The non-mutated, normal gene did not exist within the worldwide dalmatian population. So in 1973 an American geneticist called Dr. Robert Schaible carried out a single out cross to a pointer in order to reintroduce the normal gene required for normal uric acid metabolism, since then all breeding has been to purebred registered Dalmatians.
We are now 20+ generations into this breeding programme and it is hoped that one day we can eliminate the defective gene from the dalmatian population.
We are proud to say that we at Tippledal are now part of this revolution. Both Peachy and Archie carry the LUA gene, so at least 1/4 of their puppies (statistically) will inherit the LUA gene. Any HUA puppies, given the correct food and ensuring lot of fluids and toilet breaks are incorporated into their daily routine, they should not suffer from urate stone problems.
More about the gene and science behind it: The Gene for Uric Acid Metabolism
The canine digestive system has evolved so that certain proteins called purines are metabolised into uric acid. Uric acid is then converted into allantoin which is excreted without harm. The gene responsible for doing this is SLC2A9.
In Dalmatians, SLC2A9 has undergone a mutation and no longer functions. Uric acid is not converted into harmless allantoin. Instead it accumulates in the urinary tract, most notably the bladder, and creates a condition known as hyperuricosuria in which the level of uric acid is so high that it may form urate crystals. The mutation that causes this is called the HUA (or High Uric Acid) gene.
We were unlucky that an important gene for spotting was situated next to the HUA gene, and genes next to each other tend to be inherited together. As past breeders selected for better spots, they unknowingly also selected for high levels of uric acid.
All Dalmatians, except for those originating from the Dalmatian back cross project, have two copies of a recessive mutant gene, which means they are unable to process uric acid correctly. This results in abnormally high levels of uric acid in their urine and a predisposition to form urate stones in the bladder and sometimes the kidneys; this can cause urinary obstruction (a potentially fatal medical emergency).
The Dalmatian Back cross Project hopes to eliminate this condition (see below). LUA dalmatians have a copy of the normal dominant gene, enabling the body to process uric acid correctly. This eliminates their predisposition to bladder, resulting in a dog that can eat a wider variety of foods that would otherwise have led to the risk of these stones forming.
All dogs have two copies of SLC2A9. The LUA (or Normal Uric Acid) version is dominant(N), and the mutant HUA gene is recessive (hu), as such a dog only has to inherit one copy of the 'LUA gene' in order to be able to process purines normally. HUA x HUA mating will only produce HUA puppies, in the same way that a liver x liver mating will only produce liver puppies.
The possible combinations and their effect on uric acid levels are as follows:
The problem? Hyperuricosuria - Bladder Stones
All Dalmatians, except for those originating from the LUA Dalmatian back cross project, have two copies of a recessive mutant gene (hu/hu), which means they are unable to process uric acid correctly. This results in abnormally high levels of uric acid in their urine and a predisposition to form urate stones in the bladder and sometimes the kidneys; this can cause urinary obstruction (a potentially fatal medical emergency).
The improvement? The LUA gene
LUA dalmatians possess at least one copy of the non-mutated, correct gene (heterozygous N/hu or homozygous N/N) which allows them to process uric acid correctly.
HUA dals have 2 copies of the defective gene and cannot properly metabolise purines. LUA dals have one or two copies of the wild (normal) gene that permits proper purine metabolism. The wild gene is dominant, so even with only one gene, the dog can properly metabolise purines.
How was this gene incorporated into the breed? The Dalmatian Backcross Project & 'LUA' or 'NUA' Dalmatians
The non-mutated, normal gene did not exist within the worldwide dalmatian population. So in 1973 an American geneticist called Dr. Robert Schaible carried out a single out cross to a pointer in order to reintroduce the normal gene required for normal uric acid metabolism, since then all breeding has been to purebred registered Dalmatians.
We are now 20+ generations into this breeding programme and it is hoped that one day we can eliminate the defective gene from the dalmatian population.
We are proud to say that we at Tippledal are now part of this revolution. Both Peachy and Archie carry the LUA gene, so at least 1/4 of their puppies (statistically) will inherit the LUA gene. Any HUA puppies, given the correct food and ensuring lot of fluids and toilet breaks are incorporated into their daily routine, they should not suffer from urate stone problems.
More about the gene and science behind it: The Gene for Uric Acid Metabolism
The canine digestive system has evolved so that certain proteins called purines are metabolised into uric acid. Uric acid is then converted into allantoin which is excreted without harm. The gene responsible for doing this is SLC2A9.
In Dalmatians, SLC2A9 has undergone a mutation and no longer functions. Uric acid is not converted into harmless allantoin. Instead it accumulates in the urinary tract, most notably the bladder, and creates a condition known as hyperuricosuria in which the level of uric acid is so high that it may form urate crystals. The mutation that causes this is called the HUA (or High Uric Acid) gene.
We were unlucky that an important gene for spotting was situated next to the HUA gene, and genes next to each other tend to be inherited together. As past breeders selected for better spots, they unknowingly also selected for high levels of uric acid.
All Dalmatians, except for those originating from the Dalmatian back cross project, have two copies of a recessive mutant gene, which means they are unable to process uric acid correctly. This results in abnormally high levels of uric acid in their urine and a predisposition to form urate stones in the bladder and sometimes the kidneys; this can cause urinary obstruction (a potentially fatal medical emergency).
The Dalmatian Back cross Project hopes to eliminate this condition (see below). LUA dalmatians have a copy of the normal dominant gene, enabling the body to process uric acid correctly. This eliminates their predisposition to bladder, resulting in a dog that can eat a wider variety of foods that would otherwise have led to the risk of these stones forming.
All dogs have two copies of SLC2A9. The LUA (or Normal Uric Acid) version is dominant(N), and the mutant HUA gene is recessive (hu), as such a dog only has to inherit one copy of the 'LUA gene' in order to be able to process purines normally. HUA x HUA mating will only produce HUA puppies, in the same way that a liver x liver mating will only produce liver puppies.
The possible combinations and their effect on uric acid levels are as follows:
This is the same way that the recessive gene for liver spotting (b) works. Two copies of bb are necessary for a liver Dalmatian. Bb or BB results in a black-spotted Dalmatian.