Let me first start that this is NOT a disease or affliction or genetic disorder found solely within the Peruvain Paso breed. I have seen DSLD in Quarter Horses, Standardbreds, Arabians, and many other breeds as well. However one will not find the disorder (or whatever you choose to categorize it as) in other breeds to the extent that you find it within the Peruvian breed. My thoughts for this are written below.
Keep in mind THESE ARE MY THOUGHTS AND OPINIONS BASED ON MY OWN PERSONAL EXPERIENCE within this breed. They are not scientific facts, they have not been proven as I feel they should be by genetic testing. When and if a test becomes avaialble I think most of you will find I was right on this, whether or not you like what I have to say on the matter.
No, I am not a vet. So why would I be qualified to speak on the matter? Well to be honest with you, I probably have seen MORE cases of DSLD through my experiences with the Peruvian Paso breed than all or most vets combined that 'do' have any experience with this affliction. I have worked at some of the largest Peruvian ranches in this country at one time or another. I at one time owned with my ex husband one of the largest and most successful ranches of this breed in California. I know what I am talking about. I can also pretty much guarantee you that I can go to visit any ranch in this country un-announced and will probably find what I would call "DD" horses as well as "Dd" horses being used in each and every breeding program.
I have delivered literally hundreds and hundreds of foals within this breed. I am the breeder of hundreds of registered horses, I have bred dozens of National Champions and I am one of only a very small handful of Americans to have bred a 3 time U.S. National Champion of Champions Breeding Stallion & Laureado. I have been to Peru on numerous occaissions and have pretty much seen and done it all within the Peruvian breed.
After over 30 years in this breed, I have decided to switch breeds to a less problem prone gaited breed, the Tennessee Walking Horse. They do not have the beauty, grace or brio of the Peruvian, but they have something the average Peruvian does not, which is the almost non-existent leg problems and larger size - which is a bit more appealing to most Americans.
I can not even begin to tell you the number of Peruvians I have put down over the years, not to mention the ones that I know of personally that were put down over the years that were owned by other people/ranches. I have, just for my own personal reference kept diaries of horses that were DSLD suspect or that I knew for a fact were destroyed because of this affliction, and I know for a FACT that this is hereditary and can be found with frightening regularity within certain lines. That said without mentioning "actual" names of horses (Which I am happy to provide to people privately) Here are my thoughts and opinions.
First and foremost I DO BELIEVE that DSLD is GENETIC. I believe it is a DOMINANT GENE and that it can be found in both a DD, a Dd and dd form. I believe it is found in both the not so drastic (But very hereditary and still problematic) 'Heterozygous' form (Dd) and the devastatingly horrible "Homozygous" form (DD) as well as the non-carrier (dd). I personally believe at least 50% of the Peruvian population (more likely than not, an even a higher percentage) to be afflicted in the heterozygous stage (Dd).
Now with that in mind (and remember even a "dd" horse could produce a DSLD horse if bred to either a "DD" or "Dd") I have only ever known personally 2 stallions that I would say for a fact were most likely "dd", or totally NON-CARRIERS. Those two stallions being SOBERANO & *DOMINGUITO. Both lived well into their twenties, both had LONG, tried and true show careers and BOTH were ridden regularly and with totally clean legs well into their twenties. (They are the only two stallions I will mention by 'their correct names"
in this entire article as in both cases they are mentioned in a 100% positive light, I had both in my care up to the times of their deaths and I rode both on a regular basis as older aged horses- neither one EVER had any suspensory ligament problems or changes in their structural conformation at any time throughout their lives).
I'm sure there are dozens of others out there that I don't mention as I am only mentioning those that I had first hand experience with and that I know for a fact lived into their twenties, totally sound and rideable until the time of their deaths.
I believe that DSLD in it's Dd form afflicts many more horses than people know of. A Dd horse can be seemingly sound his entire life and then all of a sudden either totally breaks down unexplained or maybe sustains an injury at a latter age that results in the incorrect healing process that ends up as DSLD affliction. I have an older gelding at this time that is 23 years of age. He is a two time U.S. National Champion of Champions Performance Horse/Gelding. He has had a WELL USED life of heavy riding, extreme musical excercise riding, gymkhanas, trails etc.... He is still sound and rideable today but as of late I notice his stifles becoming straighter and his rear legs becoming more and more post legged. I am sure within the next few years I will see DSLD finally set in and when it does I will euthanize him but for now he is healthy, happy and pain free, but also retired. He is what I would call a Dd horse because while it took a long time in coming, I do see at 23 years of age the beginning signs of DSLD coming on. I think more of you breeders actually see this than care to admit. Horses break down and you euthanize them and then sweep the whole nasty little incident under the carpet.
Now DSLD in it's more severe case, is a horse that I would say was "DD". "DD" horses have drastic DSLD show up at an early age. These "DD" horses can seemingly breakdown overnight and sometimes for no apparent reason. Just as a HOMOZYGOUS GREY horse 'greys out" faster that a HETEROZYGOUS GREY, so does a "DD" horse exhibit earlier and more severe signs of the affliction than a "Dd" horse does.
Back in the 70's and 80's as well as early 90's you saw a lot more of this than you do today. At least today people are making an honest effort to avoid breeding horses with the affliction. Back then there would be al kinds of excuses as to why a horse was broken down that way. I have heard every excuse from "He got his leg caught in a fence and it ended up that way" to "The chalan did it to him" to "She had pneumonia as a baby and it settled in her back legs" (HUH??!!??? Pneumonia of the back legs??? Come again???) Breeders literally had dozens of DSLD afflicted mares in their herds and DSLD afflicted stallions as major herd sires. There were the usual run of excuses but bottom line is that most breeders back then were willing to put up with the affliction in order to get the phenomenal gaits that some of these lines possessed.
I remember the many occaissions that I have seen certain stallions that were so horribly broken down they could barely stand, many of which bred full books of mares each year because of their wonderful ability to pass on "Pisos". Some of these stallion get, grand get and great grand get I have been following for over 30 years! Guess what??? IT IS 100% HEREDITARY!!
Anyone wanting my list of horses I HAVE KNOWN, RIDDEN or SEEN perosnally over the years that I feel were DD and Dd afflicted, just write me. I'll send you my list, keep in mind this is my theory only and these are my opinions.
Don't be emailing me telling me I don't know what I'm talking about or that this does not really exist or that I am bashing certain lines because to do so will only show your ignorance on the problem and your lack of help in finding a solution. The truth of the matter is that I have never seen a breed more guilty of having their head in the sand than the owners/breeders of the Peruvian Paso Horse. Until you people get a genetic test and BAN ALL "DD" horses as well as "Dd" horses from breeding you will never be able to promote this breed and achieve the sales with the prices you should be getting. You people have created a stigma within that breed and only you CAN CLEAN IT UP!!
Unfortunately, one of the things I do think is true, is that you are going to find that actual "dd" horses amount to about 25% or less of the breeds population and that in order to save this breed from the devastation of severe inbreeding to eliminate this problem, you are more likely than not going to have to introduce some non-Peruvian gaited breeds into your gene pool. SAD BUT TRUE.