§ Toxic plants · Sapindaceae · Checked Oct 2026
Is horse-chestnut toxic to cats and dogs?
Yes. Horse-chestnut (Aesculus hippocastanum) is toxic to cats and dogs, according to the ASPCA Animal Poison Control Center. Plant Smart rates its effects Severe, level 3 of 4.
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§ 010 · Signs
What to watch for
Signs include vomiting, diarrhea, dullness or depression, dilated pupils, coma, seizures, belly pain, weakness, tremors and lying down and unable to get up. 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 Sapindaceae plants toxic to pets
Horse-chestnut belongs to the Sapindaceae family. ASPCA lists these relatives too.
§ 040 · Questions
Questions about horse-chestnut and pets
Is horse-chestnut toxic to cats?
Yes. ASPCA lists horse-chestnut as toxic to cats.
Is horse-chestnut toxic to dogs?
Yes. ASPCA lists horse-chestnut as toxic to dogs.
What happens if my pet eats horse-chestnut?
Signs include vomiting, diarrhea, dullness or depression, dilated pupils, coma, seizures, belly pain, weakness, tremors and lying down and unable to get up. Plant Smart rates it Severe, level 3 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.