Yes, hydrangeas are mildly toxic to cats
Hydrangeas contain cyanogenic glycosides. In pets, poisoning usually causes stomach upset only; the large amounts needed for cyanide-like effects are rarely eaten.
Hydrangeas and cats: key facts
| Toxic to cats? | Mildly toxic |
| Toxic to dogs? | Mildly toxic |
| Scientific name | Hydrangea arborescens and macrophylla |
| Also called | hortensia, seven bark |
| Toxic compound | Cyanogenic glycosides |
| Toxic parts | Leaves, buds and flowers |
| Signs usually start | Usually within a few hours |
| Plant type | Garden plant |
Symptoms of hydrangeas poisoning in cats
- Vomiting
- Diarrhea
- Depression
Why hydrangeas are toxic to cats
These glycosides can release cyanide when the plant is chewed and digested. In practice pets eat too little for cyanide poisoning, so the usual result is stomach upset.
What to do if your cat ate hydrangeas
- Remove plant pieces from your cat's mouth and move cats away from the plant. Wipe sap or pollen off the fur and paws with a damp cloth.
- Call your vet or animal poison control for advice: ASPCA Animal Poison Control: (888) 426-4435 · Pet Poison Helpline: (855) 764-7661.
- Identify the plant. Take a photo or bring a piece (or the plant label) to the vet, and estimate how much was eaten and when.
- Do not make your cat vomit unless a vet tells you to. Home remedies such as hydrogen peroxide or salt can cause serious harm, and hydrogen peroxide is not safe for cats.
- Watch for vomiting, diarrhea, depression. Go to a vet if signs are severe, last more than a day, or your cat has trouble breathing or swallowing.
Treatment and outlook
Supportive care for vomiting and diarrhea is usually all that is needed. See a vet urgently if your pet has trouble breathing, bright red gums or collapses.
How to keep your cat away from hydrangeas
- Place hydrangeas on high shelves or in hanging planters away from furniture cats can climb, or in a room your cat cannot enter.
- Give your cat something better to chew: a pot of cat grass or catnip often distracts cats from houseplants.
- Pick up fallen leaves, petals and pollen promptly, and empty vases where pets can reach them.
- In the garden, fence off beds, supervise cats that dig, and store bulbs in a closed container before planting.
Pet-safe alternatives to hydrangeas
If you love flowers, these are listed as non-toxic to cats by the ASPCA:
- LilacsNon-toxic
- RosesNon-toxic
- OrchidsNon-toxic
- SunflowersNon-toxic
- Gerbera DaisiesNon-toxic
- Christmas CactusNon-toxic
- Spider PlantsNon-toxic
- Money TreesNon-toxic
See the full list of plants safe for cats.
Hydrangeas and cats: FAQ
Are hydrangeas poisonous to cats?
Hydrangeas are mildly toxic to cats. Cyanogenic glycosides can cause vomiting and diarrhea, but serious poisoning is uncommon.
What part of hydrangeas is toxic to cats?
Leaves, buds and flowers.
Can cats die from eating hydrangeas?
It is very unlikely. Hydrangeas usually cause mild, short-lived signs. See a vet if signs are severe or your cat has trouble breathing or swallowing.
How long after eating hydrangeas will my cat show symptoms?
Usually within a few hours.
Are hydrangeas toxic to dogs too?
Yes, hydrangeas are mildly toxic to dogs.
Other plants toxic to cats
- Peace LiliesMildly toxic
- Calla LiliesMildly toxic
- TulipsMildly toxic
- HyacinthsMildly toxic
- CarnationsMildly toxic
- DaisiesMildly toxic
- ChrysanthemumsMildly toxic
- Baby's BreathMildly toxic
Sources
- ASPCA Animal Poison Control: Toxic and Non-Toxic Plants for Cats
- Merck Veterinary Manual: Poisonous Plants
Toxicity ratings follow the ASPCA Animal Poison Control Center plant lists. Severity depends on the amount eaten, the part of the plant and your cat's size and health. When in doubt, call your vet.