I've had horses for years and never had an incident until now. I recently put my horse on MSM for joint maintenance. After taking a couple bites of grain he suddenly lowered his head to the ground and opened his mouth letting the grain fall out of his mouth. He didn't spit the grain out, but merely let it fall and began kicking his belly and wanting to lay down and roll.
Thinking it was just a weird one-time deal, I tried it again the next day and he gave me the same reaction. Head down, grain falling out of his mouth, and kicking at his belly wanting to lay down. I know it wasn't the MSM because it's being given to mutliple horses and they are all fine. Just wondered if anyone else has experienced something similar.