Are acorns bad for my horse to eat?

Short answer: yes.  Long answer: also yes.  But you should read the article anyway!


Acorns are the seeds of oak trees, and most oak trees need to be around for 20 to 50 years before they start to produce acorns.  If you do have an oak tree around your horses, you also need to be worried about the leaves and buds as well as the acorns.  


A typical acorn, filled with tannins and poisonous for horses. 

Acorns contain tannins, which are bitter and toxic.  Tannins, in small doses, are relatively harmless to horses.  Larger doses are poisonous, and can be deadly.  The tannins interfere with how protein is metabolized by your horse.  The poisoning can lead to ulcerations, kidney failure, gastrointestinal issues, constipation, diarrhea, colic, dehydration.  That’s a long list of uncomfortable, complicating, and expensive Veterinary bill creating.  There is no antidote for acorn poisoning, so your horse must be treated symptomatically with supportive care and hopes he can recover.  Often, you may find your horse sick and unless you see him eating away at acorns you may not know why he’s having some distress.  But it’s a good thing to pay attention to!


Know what types of trees are around your horses. 


So a few questions are obvious - how many acorns does your horse need to eat to get poisoned?  There is no answer to this question, as every horse is different and the level of poisoning also relates to how much forage your horse is eating at the time.  So he’s munching on a flake of hay and eats a few acorns?  No big deal.  He has forsaken his hay and is now trying to eat the entire oak tree?  Big issue.  So bottom line is that oaks and horses are not ideal to live together in any quantity. 


It should also be noted that some horses develop an acorn addiction, which is why they often ignore their regular meals and only consume acorns, oak leaves, and buds, some venturing as far as to eat bark and limbs, too.  Other horses don’t care at all about acorns.  


Here I am riding amongst several oak trees.  These don't yet produce acorns, and the barn and paddocks are far removed from the trees.  


So what do you do?  Bottom line is that oak trees may provide spectacular shade and beauty on your farm.  On the half of the farm that the horses don’t live on.  Creating paddocks and horse areas away from oak trees is ideal, and pay attention to the weather.  Storms, seasons, wind can all carry acorns and leaves into horse paddocks and stalls.  Have a plan for dealing with this before your horse’s go out again with acorns.  Does anyone have a vacuum for their paddocks?


How do you deal with acorns and your horses?