Why it's dangerous
The plant contains cardiac glycosides which interfere with the heart's electrical activity and cause gastrointestinal irritation.
Toxic compound: cardiac glycosides
How vets treat it
No treatment plan written for cats was found. Massey University's notes on the spindle tree list washing out the stomach (gastric lavage) and activated charcoal. If heart signs develop, the Merck Veterinary Manual's treatment for plants that contain cardiac glycosides, a group in which it doesn't list euonymus, includes IV fluids, close monitoring of blood electrolytes, atropine for a slow heart rate and medicines for abnormal heart rhythms.
Outlook
No survival figures for cats were found. Pet Poison Helpline says pets that eat several leaves or seeds commonly get stomach upset, and that an irregular heart rhythm and collapse may occur after a massive ingestion. Massey University's notes on the spindle tree give a guarded outlook and say poisoning can be fatal; the deaths they describe were in horses.
Where pets are exposed
- Euonymus is a group of shrubs and small trees grown as ornamentals in gardens. Common names include burning bush (winged euonymus), spindle tree, wahoo and strawberry bush.
- Burning bush (Euonymus alatus) is a popular fall shrub, named for its bright red autumn leaves. In the fall, its red capsules split open to show orange-red seeds.
- The European spindle tree (Euonymus europaeus) grows in gardens and in the wild, in woods, scrub and hedges. In autumn, its pink to red capsules split open to show seeds wrapped in a fleshy orange coat.
- Japanese spindle (Euonymus japonicus) is common in gardens and is probably poisonous too.
- Every part of the plant can be considered toxic. The leaves, fruit and seeds contain heart toxins called cardiac glycosides (cardenolides), and the seeds also contain alkaloids.
Prevention
- If your pet eats berries or chews shrubs, don't plant euonymus where it plays, or fence the shrubs off.
- In the fall, when the capsules split open, pick up fallen berries and seeds under burning bush and spindle trees.
- Don't leave hedge clippings or pruned branches where animals can reach them. Two horses died after eating spindle tree shoots.
- Learn the other names: burning bush, spindle tree, wahoo and strawberry bush are all euonymus.
Good to know
Cardiac signs such as arrhythmias are rare and typically only occur following a massive ingestion of plant material.
Common questions
Is euonymus toxic to dogs?
Yes. The ASPCA lists euonymus as toxic to dogs, cats and horses, and names alkaloids and cardenolides as its toxins. Pet Poison Helpline says eating several leaves or seeds commonly causes stomach upset, while a massive ingestion may cause an irregular heart rhythm and collapse. The ASPCA says such massive exposures are rare in dogs. Call your vet or a pet poison line if your dog eats any part of the plant.
Are burning bush berries poisonous to dogs?
Yes. The ASPCA says all parts of burning bush can be considered toxic. Its glycosides and alkaloids irritate the digestive tract, causing vomiting, diarrhea, drooling and abdominal pain, sometimes with blood. In one ASPCA case, a Golden Retriever that vomited about 12 berries had stomach upset for a few hours and was back to normal the next morning. Massive exposures can affect the heart, so call your vet with an estimate of how many berries your dog ate.
Is euonymus poisonous to cats?
Yes. The ASPCA lists euonymus as toxic to cats, with vomiting, diarrhea, abdominal pain and weakness, and heart rhythm abnormalities with large doses. We found no published cat cases and no toxic dose for cats, so treat any chewing as urgent and call your vet.
Which part of a spindle tree is poisonous?
All of it can be considered toxic. Pet Poison Helpline names the leaves and seeds, and Massey University reports heart toxins (cardiac glycosides) in the fruit and leaves and alkaloids in the seeds. The fruit ripens in autumn, when the capsules split open to show seeds wrapped in an orange coat. Call your vet if your pet eats any part of the plant.
Is Japanese euonymus toxic to pets?
Probably. Massey University says Japanese spindle (Euonymus japonicus), common in gardens, is probably poisonous, and Pet Poison Helpline's entry covers euonymus species as a group. None of the sources we checked describes a pet poisoned by Japanese spindle, so treat any chewing as you would for other euonymus and call your vet.
Sources
- Merck Veterinary Manual — Houseplants and Ornamentals Toxic to Animals
- ASPCA Animal Poison Control Center — Toxic and Non-toxic Plants: Spindle Tree
- ASPCA Animal Poison Control Center — Falling for Fall Plants: Macy's Case (2021)
- Pet Poison Helpline — Euonymus
- Pet Poison Helpline — Burning Bush
- Massey University — Poisonous plants: Spindle tree (2007)
- NC State Extension — Euonymus europaeus (European spindle tree)
- NC State Extension — Euonymus alatus (burning bush)
- Pet Poison Helpline
This page is informational and is not veterinary advice. If your pet has been exposed to something risky, contact your vet or an animal poison control line right away.
