§ Toxic plants · Apiaceae · Checked Oct 2026
Is poison hemlock toxic to cats and dogs?
Yes. Poison hemlock (Conium maculatum) is toxic to cats and dogs, according to the ASPCA Animal Poison Control Center. Plant Smart rates its effects Critical, level 4 of 4.
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§ 010 · Signs
What to watch for
Signs include agitation, tremors, drooling, diarrhea, paralysis, belly pain, respiratory paralysis, seizures, weak pulse, respiratory failure, peeing more than usual and wobbliness or poor coordination. Eaten in quantity, it can be fatal. Signs can start within hours; some take a day or more to show.
§ 020 · If it happened
What to do if your pet ate it
Call your vet or a pet poison hotline straight away, even if your pet seems fine: the ASPCA Animal Poison Control Center, (888) 426-4435, or Pet Poison Helpline, (855) 764-7661. Both are open 24 hours and charge a fee. Have the plant or a photo of it to hand, and don’t make your pet vomit unless a vet tells you to.
§ 030 · Same family
Other Apiaceae plants toxic to pets
Poison hemlock belongs to the Apiaceae family. ASPCA lists these relatives too.
§ 040 · Questions
Questions about poison hemlock and pets
Is poison hemlock toxic to cats?
Yes. ASPCA lists poison hemlock as toxic to cats.
Is poison hemlock toxic to dogs?
Yes. ASPCA lists poison hemlock as toxic to dogs.
What happens if my pet eats poison hemlock?
Signs include agitation, tremors, drooling, diarrhea, paralysis, belly pain, respiratory paralysis, seizures, weak pulse, respiratory failure, peeing more than usual and wobbliness or poor coordination. Eaten in quantity, it can be fatal. Plant Smart rates it Critical, level 4 of 4.
What should I do if my pet ate it?
Call your vet or a pet poison hotline right away, even before signs appear: the ASPCA Animal Poison Control Center at (888) 426-4435, or Pet Poison Helpline at (855) 764-7661. Both charge a fee. Have the plant, or a photo of it, to hand.