Stoicfish, yes I am interested in the warmblood side of the story in this case because the horse clearly has symptoms. PSSM type 2 does not seem to be prevalent in the draft I understand. He is registered as a sport horse not a warmblood as such, though you’d be hard pressed to guess he was a draft cross looking at him. If I can work out how to post a photo, I’ll do it :)[/QUOTE]
This might be a good platform for education on this subject.
It is my understanding that Type 1 is definitely genetically identifiable with a test. However Type 2,
At present there is not a specific genetic test for type 2 PSSM and we do not have conclusive evidence that it is inherited.
Of greatest importance is the realization that exertional rhabdomyolysis
comprises several myopathies that, despite similarities in clinical presentation,
differ considerably in regards to pathogenesis (cellular events, reactions, and other pathologic mechanisms occurring in the development of disease).
I think this is important because it broadens the scope of the disease way beyond Type 1 and type 2. What is commonly called “Type 2” is a multifactorial issue with several causes and prevalent in many breeds of horses that undergo strenuous exercise. The article actually separates the draft “type 1” disease from the rest, “type 2”.
A similar glycogen storage disorder has been reported in draft breeds. This syndrome is referred to as equine polysaccharide storage myopathy (EPSM). While similarities exist between PSSM and EPSM, draft horses with EPSM often exhibit signs not indicative of PSSM, including normal serum creatine kinase, difficulty backing and holding up limbs, a shivers-like gait, and loss of muscle mass. Some drafts afflicted with EPSM also show recumbency and weakness with only slight increases in serum CK and AST, and this combination of signs is not seen in horses with PSSM.
When viewed this way it seems to be a common issue with most horse and as it is common in Tb’s as well as Arabs, so you will probably see it in most of the breeds that used those breeds as a basis. Some one who was tracking this progression with a large data bank may be able to shed some light on the method of heritability.
However, asking people their personal experience with horses related to yours is not going to be very helpful as there are thousands of horses related to those bloodlines and the issue is obviously not directly inherited or a recently created disease.
In other words it would be like me having an issue with a horse that had Man O War in the pedigree and asking all those with Man O War decedents if they had similar issues. Too many horses and too many factors to correlate any useful type of information.
But I’m glad you have found something that has worked for him. Have you found any information on high fat diets and insulin resistance?