Frequently (and not so frequently) Asked Questions
BRIEF: Are acorns poisonous to horses?
QUESTION:
I have a friend whose horses are eating "acorns". I have never run into this
before. It has been more than 72 hours since she noticed this and there have
been no obvious symptoms of sickness.
Acorns are not listed as a problem to horses. Is this particularly bad for
them? In their pasture, it will be hard to control. Do you think any
problem will result from this?
ANSWER:
It depends on the species of oak, how much they are eating and what else they have
to eat. If they have little else to eat, the acorns are from a high-tannin variety
and they are eating pounds of them, then protein deficiency at least and severe
tannin/polyphenolic toxicity at worst may ensue. If the horses are on full feed,
have an otherwise balanced diet and are just nibbling the occasional white oak
acorn, no harm done.