Bitsy turns into Sybil (multiple personalities--all bad) when she even
sniffs alfalfa. She rears, bucks, kicks and once when I was handling her
and she reared up, an observer said she tried to strike me. I prefer to
think she was just waving her forelegs around. :-)
When I first started asking people about this, no one believed me so I
decided that my little horse had some kind of rare allergy to alfalfa, grain,
any food that can make a horse hot and took her off all that stuff. But it
takes a long time to get back to normal. When they eat it, they get crazy
right away but getting back to sweet and normal takes forever. Weeks, even
months and I think it's because they have to unlearn the bad habits again.
That's the only explanation I have for why it takes so long. But
don't worry, your horse WILL get back to his normal self. Just keep the
stuff away from the poor guy.