Is Oak Tree (acorns) Toxic to Dogs?
Also known as: Acorns, Oak Leaves, Quercus spp. · Quercus spp.
What makes it toxic
Gallotannins in acorns and young leaves, which irritate and erode the gut lining and stress the kidneys at higher doses. Acorns also pose a choking and intestinal obstruction risk.
Warning signs to watch for
Vomiting, diarrhea (sometimes with blood), belly pain and lethargy within hours to a day. Significant ingestion can lead to weakness, increased thirst and reduced urination as kidney injury develops.
What to do if your dog eats it
Remove the acorns, note the quantity eaten and call your vet promptly — size matters, so small dogs are at higher risk per acorn. Lethargy, no urination or persistent vomiting is an ER situation.
Common questions
How many acorns make a dog sick?
It varies with dog size and acorn species, but even a handful can trigger significant GI illness in a small dog. Any real feast under the oak tree deserves a vet call.
Can acorns cause an intestinal blockage?
Yes. Whole acorns are hard and slow to break down, and a meal of them can obstruct the gut — vomiting without stool or a painful belly means urgent care.
Which is worse, green or brown acorns?
Green, unripe acorns hold more tannins. Autumn is the risky season either way, so rake or block the drop zone if your dog scavenges.
More plants checked for dogs
This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate something concerning, contact your veterinarian or a pet poison hotline right away. Checking what your pet can eat? Visit our sister site SafeOrToxic.