I have been dealing with PSSM for 18 years after breeding my mare to what I know now was a PSSM inflicted stallion.
The PSSM test, however, was not available at that time but I am able to track this to this breeding. This stallion suddenly died of "colic"at 5 years old shortly after the breeding, according to the owner. Here is my story of my three related PSSM positive horses from this one breeding.
In 1996 my mare produced a colt from this outside breeding. I eventually bred this colt to my other mare then gelded him right afterwards. This colt never really enjoyed being ridden and was ornery at times. Of course now I know why ...because he didn't feel good. I feel bad now that I know I was feeding him wrong but there was no PSSM testing then. I had to put him down at only 8 years old after he was kicked in the pasture and suddenly and strangely developing severe rapid breathing from which he could not recover. Everyone including my vet was puzzled by this. I was devastated.
I turned my attention to the filly he sired in 2000... training, riding , and showing her. I eventually had this mare bred to an outside stallion I know now was not PSSM positive. Later that same summer she started showing stress signs of heavy breathing when being ridden. Like her sire we couldn't figure out what was wrong. The next spring she produced a filly. After weaning the foal I started riding the mare again but the problems got worse. She tied up severely on a trail ride, fell asleep or fainted and just dropped to the ground while I was off holding her during a break on the trail, she developed diarrhea at shows, had muscle twitching, or would just stop while riding her and breath rapidly. I cried a lot and was totally frustrated. Nothing my vet helped me with worked.
In the fall of 2007 the vets at Minnesota State University successfully developed and patented testing for PSSM. I read about it and wondered if this could be what was wrong with my mare and also with her sire. I was completely frustrated and at wits end. I put so many years, time, energy, and training into these horses and no one could tell me what was wrong. Finally in 2008 I took my mare to Michigan State University Veterinary clinic. After a thorough exam and eliminating things such as heart problems, the PSSM test was administered on my mare and sent in for analysis. They told me my mare was the first horse in Michigan to be tested for PSSM. About two weeks later the university vet called me with the report that my mare did have PSSM and tested PSSM type 1 n/P1. I was actually relieved! I finally knew what was wrong and what to feed these horses properly to help them. I immediately had my vet test this mare’s foal, although I knew it would be positive, and of course the testing came back the same result as her mother... PSSM type 1 n/P1.
Recently I started working Moon daily in the ring to tweak her lope. After three weeks of daily work she started showing muscle twitching, had a 103 temp and could barely walk. I took her to my vet, but her signs stopped and she was fine. We figure she had cramps and was tying up. She had never shown signs before so I thought she was going to be usable for me . I had plans on showing her and taking her on a recent trail ride up north but all that ended when she got sick. I was once again heart broken and felt like throwing in the towel. I'm tired of 18 years of this and its such a let down. I just went in the house and sat for awhile and didn't go back to the barn. I thought about putting both horses down. I love my horses however so it's very hard to give up on them. Chicquita wins a lot in halter classes and Moon is a little cutie loaded with dun factor. Still Its expensive to feed hay to two horses I can't use the way I want because I can't trust them not to tie up. Regardless of the correct feeding I cannot show in riding events or trail ride anywhere with any kind of hilly ground, only on the flat. I will never breed either of these two mares. I am afraid someone would breed them regardless if I got rid if them. Had I known then what I know now I never would have bred my mare in the first place.
PSSM should not be passed on and breeders must help eliminate this muscle disease from the horse industry. PSSM causes many many years of anguish and sadness to owners and creates suffering to these poor animals. The registries should require PSSM testing on registration papers just like they do HYPP. I requested a list of known PSSM positive horses from the vet at Minnesota state university but she stated they could not divulge that information due to "patient confidentiality". This is wrong. The owners may be embarrassed or even lose money but it has to be done. All PSSM positive owners should be alerted as well. Not all people know to ask a horse seller or stallion owner if their horse has been tested for administrated beforehand. With the development of PSSM testing, breeders must be responsible and have their horses tested and by all means not breed PSSM positive horses. By doing so breeders are continuing to pass this muscle disease on to the animals we love. REPRINTED WITH PERMISSION