§ Toxic plants · Apiaceae · Checked Oct 2026
Is water hemlock toxic to cats and dogs?
Yes. Water hemlock (Cicuta maculata) is toxic to cats and dogs, according to the ASPCA Animal Poison Control Center. Plant Smart rates its effects Critical, level 4 of 4.
Get a permanent discount if you join Early Access. iPhone and Android, in the contiguous U.S.
§ 010 · Signs
What to watch for
Signs include diarrhea, seizures, tremors, belly pain, dilated pupils, fever, bloating and slow, shallow breathing. 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
Water hemlock belongs to the Apiaceae family. ASPCA lists these relatives too.
§ 040 · Questions
Questions about water hemlock and pets
Is water hemlock toxic to cats?
Yes. ASPCA lists water hemlock as toxic to cats.
Is water hemlock toxic to dogs?
Yes. ASPCA lists water hemlock as toxic to dogs.
What happens if my pet eats water hemlock?
Signs include diarrhea, seizures, tremors, belly pain, dilated pupils, fever, bloating and slow, shallow breathing. 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.
What else is water hemlock called?
Water hemlock is also sold or known as common water-hemlock, victorin's water-hemlock, spotted water-hemlock and bolander's water-hemlock.