I agree with you 99% Any bunny.
I grew up with wild plants. The VERY 1st. thing I was taught before I went to school were the plants which were "deadly poisonous".
I am very aware of the potential for inexperienced people to misidentify, certain plants & try to stick to those which cannot be confused with bunny poisonous plants. There is the matter of collecting from safe places.
Cow parsley was commonly fed to buns in small amounts in my childhood - it is known by several names & commonly referred to as wild chervil, in flower identification books. It is a classic which can be misidentified.
Hemlock as rightly said can kill a cow, horse, or human, by paralysis of repiratory muscles. I am deeply concerned by it's appearance in this & other areas, the rapidity of it's spread over the last 3 years, & the total indifference of the parks department to its eradication from parks or roadside verges. Should it get in a hay field it's big trouble!
There is also the rarer rough leaved chervil, which is very difficult to distinguish from young cow parsley. It causes severe loss of balance in cattle & horses.
There are a few others which are "inadvisable" eg wild carrot.
It had a totally unexpected "side effect" on my bun, as well as some very useful effects. Another stasis bun had the same side effect, but the majority of buns including my childhood bun don't seem to get this!
My own bun has 2 main conditions. Gradual loss of nerve supply to the gut has caused issues with dysbiosis & stasis. Minor molar spurs prevented him from drinking water, & predisposed to urinary sludge because of low urine output. I have not used wild plants medicinally. I have used them to maximize gut function to reduce the number of stasis episodes.