Is Deadly Nightshade Poisonous? – Toxicity to Humans, Dogs, and Cats

Deadly nightshade is highly toxic to humans, dogs, cats, and horses. All parts of the plant contain tropane alkaloids, and a small amount can cause serious harm. The glossy black berries taste mildly sweet, which makes them especially dangerous for curious children and pets. This is one of the few plants where any suspected ingestion warrants an immediate call to emergency services.

Why Deadly Nightshade Is So Dangerous

The plant (Atropa belladonna) contains a group of alkaloids including atropine, hyoscyamine, and scopolamine. These block the neurotransmitter acetylcholine throughout the body, producing what toxicologists call an anticholinergic syndrome. The effects are systemic and affect the heart, eyes, digestive system, and nervous system simultaneously.

The ASPCA lists nightshade species (including Solanum nigrum, which shares the “deadly nightshade” common name) as toxic to dogs, cats, and horses, citing solanine, saponins, and atropine-like substances as toxic principles. Atropa belladonna represents the severe end of nightshade toxicity due to its high alkaloid content.

Every part of the plant is toxic: roots, stems, leaves, flowers, and berries. The roots are generally the most concentrated source, but the berries carry enough toxin to be life-threatening, particularly for children.

Symptoms of Deadly Nightshade Poisoning

Dogs and cats

• Hypersalivation followed by dry mouth
• Dilated pupils
• Rapid heart rate
• Disorientation and behavioral changes
• Weakness and incoordination
• Drowsiness and CNS depression
• In severe cases: seizures, coma, respiratory failure

Humans and children

The classic anticholinergic syndrome in humans includes:

• Dry mouth and difficulty swallowing
• Flushed, dry, hot skin
• Dilated pupils and blurred vision
• Rapid, irregular heartbeat
• Urinary retention
• Confusion, agitation, and hallucinations
• High fever
• Seizures and coma in severe ingestion

In a child, a small number of berries can be life-threatening. The mildly sweet taste of the berries means children do not always stop eating on their own.

What to Do

1. Call emergency services (911) or poison control at 1-800-222-1222 (US) immediately. Do not wait for symptoms to develop.
2. For pets, call your vet or an emergency animal poison line without delay.
3. Do not induce vomiting unless a medical professional directs you to.
4. If the person is unconscious, do not give anything by mouth.
5. Bring a sample of the plant or a photo to help emergency responders identify it.

This is a genuine emergency. Anticholinergic poisoning can escalate rapidly, and treatment is most effective when started early.

Identifying Deadly Nightshade

Knowing the plant helps you avoid it and identify it in an emergency:

• A perennial shrub or herb that can reach 1 to 2 meters tall
• Leaves are large, oval, dull green, and softly hairy; they have an unpleasant smell when crushed
• Flowers are drooping and tubular, purple-brown on the outside and greenish inside
• Berries are glossy black when ripe, roughly cherry-sized, growing singly from the stem
• The berries have a mild sweet taste, which increases the danger

Safe Handling

Deadly nightshade grows wild across Europe and has naturalized in parts of North America. It prefers disturbed ground, hedgerows, and forest margins.

• Never touch the plant without gloves; wash hands thoroughly after any contact.
• Wear eye protection when cutting or clearing infested areas, as sap in the eyes is dangerous.
• If you find it growing in a yard with children or pets, remove it carefully and dispose of it in a sealed bag.
• Teach children never to eat any wild berries they find.

Frequently Asked Questions

How many berries does it take to harm a child? Specific doses vary by body size and individual sensitivity. Even a small number of berries can cause serious symptoms in a young child. Treat any suspected ingestion as an emergency and do not wait for symptoms.

Is deadly nightshade the same as black nightshade? No. Black nightshade (Solanum nigrum) is a different and much less toxic plant that also carries the “nightshade” common name. Atropa belladonna is the true deadly nightshade. Solanum nigrum berries typically cause gastrointestinal symptoms; Atropa belladonna causes the full anticholinergic syndrome and is far more dangerous.

Can touching the plant cause poisoning? Serious systemic poisoning from skin contact alone is unlikely in adults. However, toxins can be absorbed through mucous membranes, and sap in the eyes is dangerous. Always wear gloves and wash hands after handling.

Why is it called belladonna? The name means “beautiful woman” in Italian. Historically, women used diluted extracts of the plant to dilate their pupils, which was considered attractive at the time. This practice carried real risk of poisoning.