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Is Henbane Toxic to Cats?

☠️ ToxicSeverity: Severe
✅ 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 — henbane is severely toxic to cats. Its tropane alkaloids disrupt the nervous system and can cause rapid heartbeat, overheating, seizures and death.

Also known as: Stinking Nightshade, Black Henbane, Hyoscyamus niger · Hyoscyamus niger

What makes it toxic

Tropane alkaloids, mainly hyoscyamine and scopolamine, throughout the plant and concentrated in seeds. They block acetylcholine receptors, producing anticholinergic poisoning: heart racing, dry membranes, delirium, convulsions.

Warning signs to watch for

Dilated pupils, rapid heart rate, dry mouth, vomiting, disorientation, aggression or agitation, then tremors, seizures, overheating and respiratory failure. Signs usually begin within an hour.

What to do if your cat eats it

This is an emergency. Go to a veterinary ER immediately, bringing a sample or photo of the plant. Do not wait for symptoms — anticholinergic poisoning escalates fast and needs hospital care.

Common questions

Is touching henbane dangerous for a cat?

Contact alone is less risky than eating, but sap on fur gets groomed off and swallowed. Wipe the coat with a damp cloth if the cat brushed the plant.

Are henbane seeds the worst part?

Yes — seeds carry the highest alkaloid load, but every part is dangerous. There is no safe portion of the plant.

More plants checked for cats

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.