Toxicity level
MildModerateSevere
- Contains cyanide-like compounds
- Within hours
- Affects: Gut
Did you know? Large amounts can cause cyanide-type effects, but usually just GI upset.
Verdict
Feed only in moderation
Key concern
Cyanogenic glycoside
Species
🐶 Dogs
Why this verdict for dogs
Hydrangea leaves, flowers and buds contain a cyanide-releasing compound. A dog would need to eat a fair amount to be seriously affected, but it commonly causes vomiting and diarrhea.
Warning signs to watch for
- Vomiting
- Diarrhea
- Lethargy
🍽️ Feeding it safely?
Frequently asked questions
Can dogs eat hydrangea?
In moderation. Hydrangea leaves, flowers and buds contain a cyanide-releasing compound. A dog would need to eat a fair amount to be seriously affected, but it commonly causes vomiting and diarrhea.
How much hydrangea can dogs have?
None — hydrangea is not safe for dogs and should be avoided entirely. When in doubt, ask your vet.
Is hydrangea safe for cats too?
Verdicts can differ between species. See the cat answer for hydrangea →
More plants for dogs
By the CanMyPet Editorial Team · Reviewed against ASPCA Animal Poison Control, the American Kennel Club (AKC) and Pet Poison Helpline · Last updated June 22, 2026.
Sources
- ASPCA — People Foods to Avoid Feeding Your Pets
- American Kennel Club — Dog Nutrition
- Pet Poison Helpline — Poison List
CanMyPet provides general information reviewed against trusted sources (ASPCA, AKC, Pet Poison Helpline). It is not a substitute for professional veterinary advice. When in doubt, always contact your veterinarian.