|© Tim Flach from his book "Dogs"|
Shar-pei Fever is an auto-inflammatory condition that experts estimate affects one in four of the breed. The fevers are transitory - usually lasting just a few hours - and feature a roaring temperature, aching joints and, sometimes, very swollen hocks. Shar-pei Fever is also known as swollen hock syndrome for this reason.
Although for most dogs the fevers are relatively benign and do not shorten their lives, it's thought that up to one in five dogs go on to develop amyloidosis - the build -up of amyloid in the dog's kidneys and, to a lesser extent, the liver, spleen and gastro-intestinal tract. It is the result of chronic inflammation and can be fatal. A lot of Shar-pei die, often young, because of it.
Now, after a 20-year hunt for answers, researchers have found that the fevers/amyloidosis are triggered by an excess of hyaluronon (HA) - the same substance that gives the Shar-pei its trademark wrinkles. It could herald bad news for breeders who feel that a Shar-pei wouldn't be a Shar-pei without its wrinkles (although, in fact, the original dog didn't have them).
Hyaluronon is present in every tissue of our dogs' bodies (our bodies, too) and it performs many important functions, including wound-healing and helping to keep joints lubricated. Ironically, it's also used in medicine to treat inflammation, including rheumatoid and osteoarthritis and, by the cosmetics industry, to help smooth out wrinkles. In over-abundance, though, HA appears to have the opposite effect, resulting in the thickened skin folds found in the Shar-pei and - as researchers have just found - the predisposition to fevers/inflammation.
Production of hyaluronon is controlled by the HAS2 gene and the researchers found a segment of DNA near this gene that, in Shar-pei, was duplicated erroneously, sometimes multiple times - something not found in other breeds. The researchers found that both hyaluronon production and the risk of Shar-pei Fever/amyloidosis went up with the numper of copies an individual dog had of this DNA segment, suggesting that this area is involved in regulating the production of hyaluronon. Critically, the researchers found that the much less-wrinkly original "bone-mouth" Shar Pei has a slightly different version of this regulatory gene that does not predispose them to Shar Pei Fever.
|The original Shar-pei|
Well, it's a bit more complicated than that.
The researchers did indeed find that the mutation that predisposes for the fevers is found only in the Western Shar-pei (known as a "meat-mouth" due to the heavy padding round its muzzle). But, again, it is not just the mutation itself that causes the problem - it is how many copies of the mutation the dog has. The more copies a dog has, the more likely it is to develop Shar-pei Fever.
The researchers also found that some very wrinkled dogs had a low number of copies - and some much-less wrinkled dogs had a high number of copies. In other words, you cannot tell just by looking at the dogs which ones are more likely to develop Shar-pei Fever.
The researchers do seem to be hinting that there could be some correlation between phenotype and Shar Pei Fever - and of course that insticintively makes sense: more hyaluronon = more wrinkles. But this has not yet been confirmed.
The good news is that there's a DNA test on the way - one that will reveal how many copies of the mutation an individual dog carries and, therefore, how likely it is to a) develop Shar-pei Fever itself and b) how likely it is to pass on the risk to its puppies. This will provide breeders with a wonderful new tool to breed away from Shar-pei Fever and the amyloidosis that kills.
It is good to see that the Shar-Pei Club of Great Britain has an encouraging statement re the research on its website. Although I found this bit worrying: "Although revealing that one of the breeds unique features in linked to risk for a significant health issue, the Club is resolute in continuing to work to produce Shar Pei which not only look beautiful but live long, happy and healthy lives."
Of course if they really meant this, they wouldn't be breeding such wrinkled dogs in the first place. Shar-pei Fever aside, the wrinkling also predisposes the dog to other health issues - including that most Shar-pei puppies have to have their eyes 'tacked' to prevent their eyelashes turning in and damaging their eyes. And, of course, those skin folds predispose the breed to bacterial and yeast infections.
The breed suffers many other health issues, too - and has a very small gene pool for which it is now paying the price. As the Chinese Shar-pei Cub of America admits: "the reality is that few make it to age 10" (although I am impressed by the Club's Longevity Program which aims to indentify longer-living lines in order to encourage breeders to use them).
Despite efforts by some breeders to prioritise health (and many have donated DNA to the research), the truth is that the breed is in a mess. As I wrote in my March column for Dogs Today magazine (pdf downloadable here): "The cost to the dog of so many genetic and conformation problems is just so high.... I don't think anyone who truly loves dogs should buy or breed Shar-pei - unless it is part of a comprehensive, international breed conservation plan targeted at minimising physical extremes and improving genetic health. I believe this is now needed urgently if the breed is to survive."
I would also like to see the traditional Shar-pei being promoted as a viable alternative. Still bred by a handful of breed enthusiasts, the original "bone-mouth" Shar-pei is an un-exaggerated dog that almost entirely outgrows its puppy wrinkles. It is by no means immune to health problems, but not those caused by excessive wrinkling. And, as the new research reveals, it appears to have a very low risk of a painful and very unpleasant death from amyloidosis caused by Shar-pei Fever.
For some helpful discussion on the new findings, led by key researcher Dr Linda Tintle, see this thread on The Chinese Shar-pei Information and Discussion Group