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Is Crown of Thorns Toxic to Dogs?

☠️ ToxicSeverity: Mild
✅ 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, crown of thorns is mildly toxic to dogs. Chewing a stem releases caustic white latex that burns the mouth and upsets the stomach.

Also known as: Euphorbia milii, Christ Plant · Euphorbia milii

What makes it toxic

Milky Euphorbia latex with diterpene esters in all green parts, caustic to mucous membranes and skin, plus sharp spines as a physical hazard.

Warning signs to watch for

Immediate drooling, mouth pain, lip swelling, vomiting and face pawing; skin contact can redden and blister.

What to do if your dog eats it

Flush the mouth and skin with water, remove plant material and offer fresh water. Contact your vet if vomiting repeats or blistering appears.

Common questions

Is the sap toxic to humans trimming the plant?

Yes — wear gloves and eye protection. The same latex irritates human skin and eyes, which is a good reminder to keep pets out of the room during pruning.

Does the sap lose potency if the plant dries out?

Not reliably. Fresh sap is the strongest, but treat any Euphorbia material as irritating regardless of how dry it looks.

More plants checked for dogs

Pothos☠️ ToxicYes, pothos is toxic to dogs. Chewing any part of the vine releases calcium oxalate crystals thaAloe Vera⚠️ Mildly ToxicAloe vera is mildly to moderately toxic to dogs. The skin and latex layer of the leaf contain coSpider Plant✅ Non-ToxicNo, spider plants are non-toxic to dogs. A dog that nibbles the arching leaves is not at risk ofEaster Lily⚠️ Mildly ToxicEaster lilies are only mildly toxic to dogs — they usually cause stomach upset, not the fatal kiSago Palm☠️ ToxicYes — sago palm is severely toxic to dogs, with a documented fatality rate around 50% when untreBoston 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.