What are some signs that my horse has eaten a poisonous plant?
Different plants will cause different symptoms but being aware of your horse's usual behavior and noticing changes in that behavior is key. Basically the signs can fit different illnesses not having to do with poisonous plants so you'll simply have to have your horse checked out in order to get a diagnosis.
Fresian Freak...Me, too, finest animal in equine group.
I have limited experience with this area, but had one experience with a thoroughbred gelding that injested parts of a yucca plant. Whether it is poisonous or not, I can't say. What I can say, however, is that yucca will cause a severe case of colic, in my case, the worst I've seen in my 40 years of playing with horses. It might be that yucca is simply not digestible...I just can't be sure it's toxic. Quietest bowels you never could hear...Keep looking, as I'm sure there are sources floating around us horsey types. I would feel a grievous loss if I were to lose a Fresian to such an event. I had Morgans 40 years ago, with their good dispositions, and feel that a Fresian is just as nice, and almost a twin in conformation, except that size-wise, they look a little like a Morgan on steroids.Chuckle..
Other people asked questions on various topics, and are still waiting for answer. Would be great if you can take a sec and answer them