Danger! Plants. Weeds. Trees. Grass. Ugh.
You'd think you'd be safe with horses- a species that is a herbivore right?
There are several types of vegetative growth that can harm horses. This includes anything from acorns to horseweed (surprise, not for horses!)
Several other poisonous plants include buttercups, yew, privet, ferns, hemlock, horseweed, acorns, locoweed, etc. There are a lot of them out there, so make sure you do your research!
If you fear your horse has eaten any of the above in any amount, do not be afraid to call your veterinarian! It really is better to be safe than sorry!
If you want to know more, check out the following websites for more information!