So this means you are back to square one with Snickers but the fact that the other horse has a positive gene doesnt mean that she will suffer from the problem only that she has the potential too?
I've queried this as pretty much all UK native breeds and many others are known to have this inherited disposition to be at risk of getting diet related laminitis & IRS but if managed correctly can live free of it. I'm not sure if the same applies to EPSN
I thought she had stringhalt when I first looked at the video but then decided it didnt look like horses I've been around that had it - one even jumped at quite a high standard
Since she doesnt seem to be in pain it could just be a skeletal deformity that she was either born with or caused by an accident early in her life that her ligaments and muscles have adjusted too.
I'll have another look at the videos but her back end seemed to have a sort of disunited look
I don't know what you and the others think but if she was mine I'd drop the high fat diet idea for her and just keep her on the sort of diet advised for native breeds, cobs, easy keepers etc of low starch/low sugar with restricted grazing in the high fructose times of year/day.
Their diet was already low sugar/low starch before...no grain. They only got 1 and 2 lbs of a ration balancer and 40lbs of bermuda hay between the two of them a day....and some pasture when I was out there.
In also speaking to my vet yesterday, she recommends continuing with the diet and whatever Dr. Valentine suggests at this time. With Snickers not being full draft, she could very well still be positive for the Type II EPSM. She feels that Snickers gait and symptoms seem to still suggest that route. Plus, there has been a small improvement in her being able to hold her trot longer. I can always opt for muscle biopsy in the future too. I'm trying not to jump around before completing each task to be sure it is something I can rule out.