Is Arborvitae toxic to dogs?

Yes — arborvitae is toxic to dogs according to the ASPCA. Keep it well away from any dog that chews plants; reactions can be significant. Arborvitae (Thuja) is not listed on the ASPCA toxic or non-toxic plant database, so its safety cannot be confirmed there — and claims that the ASPCA lists it as non-toxic are a misattribution. All parts contain thujone (plus tropolones); thujone is a recognised neurotoxin (the regulated convulsant also found in wormwood and absinthe), most concentrated in the cones, wood and twig tips. Small nibbles typically cause gastrointestinal upset (vomiting, diarrhoea, drooling), but larger ingestions can cause neurological effects including seizures, plus liver and kidney injury; horses, goats and sheep are especially susceptible and serious livestock poisoning is documented. Because authoritative toxicology flags a real systemic hazard, treat arborvitae as toxic: keep clippings away from pets and grazing animals, and contact your vet or a poison control line straight away if any is eaten — do not assume it is pet-safe.

Arborvitae (Thuja) is not listed on the ASPCA toxic or non-toxic plant database, so its safety cannot be confirmed there — and claims that the ASPCA lists it as non-toxic are a misattribution. All parts contain thujone (plus tropolones); thujone is a recognised neurotoxin (the regulated convulsant also found in wormwood and absinthe), most concentrated in the cones, wood and twig tips. Small nibbles typically cause gastrointestinal upset (vomiting, diarrhoea, drooling), but larger ingestions can cause neurological effects including seizures, plus liver and kidney injury; horses, goats and sheep are especially susceptible and serious livestock poisoning is documented. Because authoritative toxicology flags a real systemic hazard, treat arborvitae as toxic: keep clippings away from pets and grazing animals, and contact your vet or a poison control line straight away if any is eaten — do not assume it is pet-safe. Signs usually appear soon after chewing rather than hours later — watch for drooling, pawing at the mouth, vomiting, loss of appetite, or unusual lethargy after your dog has had access to arborvitae.

Stay calm. Remove any plant from your dog's mouth and take the plant away. Note how much was eaten and when, and do not induce vomiting unless told to. Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 and follow their advice; a leaf or photo helps the vet treat it correctly.

The ASPCA classification Growli uses applies to both cats and dogs: Arborvitae is toxic to cats as well. See the full arborvitae pet-safety guide for both species.

For a similar look without the risk, see the best dogs-safe plants list — every plant there is ASPCA non-toxic to cats and dogs.