Is Hydrangea Toxic to Dogs?

☠️ ToxicSeverity: Moderate

✅ Cross-checked against veterinary poison-control guidance · Oct 2026 audit

⚠️ Educational info only. If your pet just chewed something and looks unwell, skip the reading and call your vet or Pet Poison Helpline (US): (855) 764-7661.

Yes, hydrangea is toxic to dogs. Chewing leaves or buds releases cyanogenic glycosides that cause vomiting and, at high doses, cyanide-type effects.

Also known as: Bigleaf Hydrangea, French Hydrangea, Hortensia · Hydrangea macrophylla

What makes it toxic

Cyanogenic glycosides throughout the plant, concentrated in leaves and buds. Gut digestion frees hydrogen cyanide, which blocks oxygen use in cells.

Warning signs to watch for

Drooling, vomiting, diarrhea and lethargy first. Large ingestions can bring rapid breathing, bright red gums, weakness, tremors and collapse.

What to do if your dog eats it

Remove material, note the amount eaten and call your vet. Vomiting alone gets a same-day call; any breathing change or collapse is an immediate ER run.

Common questions

Is one hydrangea leaf dangerous for a dog?

Usually just mild GI upset at that dose. The concern grows with the amount eaten — tell your vet the quantity if it was a feast.

Are dried hydrangeas a danger indoors?

Yes, they keep the glycosides. Many winter poisonings start with a dog chewing a dried arrangement.

What do vets do for hydrangea cases?

Decontamination, fluids and monitoring; severe cases get cyanide antidote therapy. Most cases never reach that stage.

More plants checked for dogs

Pothos☠️ ToxicYes, pothos is toxic to dogs. Chewing any part of the vine releases calcium oxalate crystals tha Aloe Vera⚠️ Mildly ToxicAloe vera is mildly to moderately toxic to dogs. The skin and latex layer of the leaf contain co Spider Plant✅ Non-ToxicNo, spider plants are non-toxic to dogs. A dog that nibbles the arching leaves is not at risk of Easter Lily⚠️ Mildly ToxicEaster lilies are only mildly toxic to dogs — they usually cause stomach upset, not the fatal ki Sago Palm☠️ ToxicYes — sago palm is severely toxic to dogs, with a documented fatality rate around 50% when untre Boston Fern✅ Non-ToxicNo, Boston ferns are non-toxic to dogs. Chewing a frond will not poison your dog.

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.