ADULTPLANTS
Plants / Euphorbiaceae / Crown of thorns / Toxic to dogs

Is crown of thorns toxic to dogs?

Euphorbia milii

Yes

Yes. Crown of thorns is toxic to dogs, graded low severity by NC State Extension. The agent is diterpene esters in the latex. Call your vet if a dog has eaten any.

Poison severity Low as published by the NC State Extension Gardener Plant Toolbox. Their grade, not ours.
If your dog has eaten some
  1. Take any remaining plant material out of their mouth and rinse the mouth with water.
  2. Call someone. Your own vet first. Otherwise ASPCA Animal Poison Control on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661 — both charge a fee.
  3. Take a photo of the plant, and note roughly how much was eaten and when. It is the first thing you will be asked.
  4. Do not make your dog vomit unless a vet tells you to.

What it does, and why

The agent is diterpene esters in the latex.

The white latex is a potent direct irritant to any membrane it touches.

Severe mouth pain from eating and blistering on skin.

Worth watching for. Eyes are the real emergency here. Latex rubbed into an eye can damage the cornea, and that warrants same-day attention, not watchful waiting.

Reported signs

Signs as listed by the ASPCA . Not every animal shows all of them.

What each authority says

What each authority says
ASPCA
No record page found under any name tested.
NC State Extension
Poison severity: Low · Diterpene esters in milky latex

What to keep instead

Species in this database listed non-toxic to cats and dogs, chosen for a similar look or similar care rather than at random.

PlantFamilyWaterDifficulty
Elephant bushPortulacaria afra Didiereaceae 10–21d 1/5
Zebra haworthiaHaworthiopsis attenuata Asphodelaceae 14–24d 1/5

Swapping the plant is the only measure that reliably works. Height and hanging baskets buy less time than people expect with a determined cat.

The other animal

Looking for cats? See is crown of thorns toxic to cats. Full care details are on the crown of thorns species entry.

Sources

  1. North Carolina Extension Gardener Plant Toolbox — Euphorbia milii Checked 2026-09-12.
  2. Royal Botanic Gardens Kew, Plants of the World Online — Euphorbia milii Accepted name and family. Checked 2026-09-12.
  3. Wikidata entity Q148829 — entity identity, so this record can be matched against other databases.
  4. Missouri Botanical Garden Plant Finder — Euphorbia milii Cultivation record. Checked 2026-09-12.
  5. ASPCA Animal Poison Control Center, (888) 426-4435 — emergency line, fee applies

Compiled and edited by Tony Valcarcel · 2026-09-11
Tony Valcarcel is the editor and publisher of this database, not a veterinarian. Severity is reproduced from the authority that published it and is never originated here. How this is sourced.
This page is a reference, not a diagnosis. In an emergency, call rather than read.