Low Uric Acid Dalmatians

Background

All Dalmatians, apart from those descended from the Low Uric Acid backcross project, suffer from a defect of uric acid metabolism which causes them to have an abnormally high level of uric acid in the urine, hyperuricosuria (HUU), making them vulnerable to the formation of urate crystals, sludge and stones in the urinary tract, mainly in the bladder but occasionally in the kidneys. The defect is a genetic one in which Dalmatians have acquired two copies of a mutant recessive gene leaving them unable to metabolise uric acid correctly. Other breeds are also affected, notably the English Bulldog, Black Russian Terrier and Giant Schnauzer, but the Dalmatian is the only one that has completely lost the normal dominant gene, as demonstrated by research involving large scale DNA testing of Dalmatians.

In this article, the terms low uric acid (LUA) and normal uric acid (NUA) will be used synonymously.

History

In 1973 an American geneticist who happened also to be a breeder and exhibitor of Dalmatians, carried out an outcross of a Dalmatian to an English Pointer. He recognised that the normal gene responsible for uric acid metabolism had been completely lost in the Dalmatian breed and that the only way to recover it was to outcross to another breed. The obvious choice was the English Pointer because of their common ancestry and certain common features.  

He made an outcross of an American Kennel Club (AKC) registered Champion Pointer sire, CH Sandown’s Rapid Transit, to an AKC registered Dalmatian dam, Lady Godiva. Of course the first puppies looked very little like purebred Dalmatians, but the second generation puppies, from matings with American Kennel Club registered Dalmatians looked more like typical Dalmatians and the best of those carrying a copy of the LUA gene were selected for further breeding. This became known as the LUA backcross project. LUA Dalmatian puppies are now being bred and are as many as 25 generations or more from the original outcross. At 13 generations, the genetic information was 99.98% Dalmatian, so it is clear that the only part of the original Pointer that remains is that dominant gene which Dalmatians had completely lost, making them vulnerable to the formation of urate stones in the urinary tract.

In the early days, the LUA and HUA puppies were identified by doing a urine spot test, measuring uric acid to creatinine ratios, but now a simple DNA test is available which is able to identify the exact DNA status of Dalmatian puppy from a breeding in which a parent has at least one copy of the normal gene.

The image shows the appearance of the urine from an LUA puppy (left) and an HUA puppy (right). 

The first LUA Dalmatian to leave the USA was Wendy, Stocklore Forrest Windsong, who went to a vet in France, Dominique Vincent. In 2010, Fiona, CH Fiacre’s First And Foremost, and Sally, Stocklore Sally Forth, came to the UK. Fiona was campaigned for a year in the show ring and in that time achieved one CC and a BIS. She then had a single litter while under the care of Julie Evans of Tyrodal Dalmatians, before returning to her owner Carol Chase in America. Sally remained with us and and has left the legacy of 4 generations of LUA Dalmatians in the UK and Europe. Merlin came to the UK the following year after completing a 6 month stay in Italy with a family who owned Dalmatians and had one who had suffered form stones. In this way he was able to avoid the quarantine laws which were in place at the time. He had a successful time in the show ring and sired litters in the UK, France and Germany and he now has descendants in the UK, Europe, Scandinavia and Russia.  

Today the LUA Dalmatians are found in many counties throughout the world and are diversifying through integration into many different lines. Recently the first LUA breeding has taken place in Denmark and are great grandchildren of Sally and in Spain we await the outcome of their first LUA x LUA breeding which will hopefully produce their first Dalmatians who are completely clear of the HUA gene.