My Standardbred gelding started having mild to severe tie up episodes in 2020. He lost a good amount of top line muscling and had all sorts of other health issues arise. We did bloodwork after one of his larger tying up episodes (he was unable to back off the trailer after a long trail ride because he was so stiff and in pain). The bloodwork was highly indicative of PSSM and my vet recommended doing the hair test for PSSM 1. I did that through animal genetics and then did the type 2 test through EquiSeq. He is negative for type 1 but did come back with one of the variants (n/p2) via EquiSeq.
With that in mind, we changed his feed to high protein with added cool fats. It took about 6 months for him to recover his muscle and start feeling better. Adding in 4000ius of naturally occurring vitamin E helped out a ton along with salts and electrolytes. He is in full work now, training for the hunter/jumper circuit and doing well physically. His feed right now is a mix of soy bean hulls, speedibeet, coolstance copra, salt, vitamin e, pre-ox balancer and DMG.
After a tie up we usually add magnesium and chamomile along with electrolytes. I try to do longer stretchy walk rides and hand walks too if the tie up is really extreme. That being said, he hasn’t had a true tie up episode in over a year. I do think PSSM can be managed but it requires a lot of trial and error and patience.