Is Lantana Poisonous? – Toxicity to Dogs, Cats, and Humans

Lantana is toxic to dogs, cats, horses, and humans. All parts of the plant contain pentacyclic triterpenoids (lantadenes A and B) that cause gastrointestinal upset and liver damage. The unripe green berries carry the highest concentration and are the main poisoning risk for children and pets. Liver failure is well documented in livestock following significant ingestion and is possible in companion animals with larger exposures.

About Lantana

Lantana (Lantana camara) is a flowering shrub widely grown as a garden ornamental in tropical and subtropical regions and as a summer annual in cooler climates. It is popular for its clusters of small flowers that appear in combinations of orange, yellow, red, pink, and purple. The plant is also sold under the names shrub verbena, yellow sage, and red sage.

In warm climates, lantana grows as a perennial and can become invasive. All color forms and varieties share the same toxicity profile. The ASPCA lists lantana as toxic to dogs, cats, and horses.

The berries progress from green (most toxic) to blue-black (less toxic but still harmful) as they ripen. Their berry-like appearance makes them a hazard for young children.

What Part of Lantana Is Toxic?

The unripe green berries have the highest concentration of lantadenes. The leaves are also toxic and are the most common source of poisoning in grazing animals. Flowers and stems contain lower levels of the compound. Ripe dark berries are less toxic than unripe ones but are not safe. All parts of the plant should be treated as potentially harmful.

Symptoms of Lantana Ingestion

Dogs and cats: Vomiting, diarrhea, weakness, and lethargy are common early signs. With larger ingestions, labored breathing and liver damage may develop. Signs of liver involvement, such as yellowing of the skin or eyes, dark urine, or loss of appetite in the days following exposure, require prompt veterinary attention. Most pets recover from mild exposures with supportive care.

Horses: Liver failure is the primary concern after ingestion of significant plant material. Symptoms include photosensitivity (skin lesions from sun exposure), jaundice, weakness, and neurological signs. Lantana poisoning in horses and cattle is a documented veterinary emergency in tropical and subtropical farming regions.

Humans and children: Nausea, vomiting, stomach pain, and diarrhea are the most common effects from berry ingestion. Children who eat a significant number of unripe green berries face the greatest risk. Serious liver toxicity in humans from lantana is rare but has been documented.

What to Do If Someone Ingests Lantana

1. Remove any berries or plant material from the mouth.
2. Do not induce vomiting unless directed by a medical professional.
3. Call poison control at 1-800-222-1222 (US) or your vet immediately.
4. Note whether the berries were green (unripe) or dark (ripe), and estimate how many were consumed.
5. Seek emergency care if jaundice, dark urine, or severe weakness develops in the days following ingestion, as these suggest liver involvement.

Liver effects from lantadenes may take one to three days to become fully apparent. Follow up with a vet even if initial symptoms seem mild after berry ingestion.

Safe Handling and Keeping Pets and Children Safe

• Fence off or relocate lantana plants to areas that young children and pets cannot access.
• Remove spent flower heads and developing berries promptly, especially before the green berries ripen.
• Wear gloves when pruning or handling lantana; the leaves and sap can cause skin irritation on contact.
• In regions where lantana grows as a roadside or garden weed, keep pets on leash in areas with heavy lantana growth.
• For pollinator-friendly planting without the toxicity risk, consider bee balm (Monarda), catmint (Nepeta), or native coneflowers (Echinacea) as alternatives.

Frequently Asked Questions

Are ripe dark lantana berries safe to eat? No. Ripe berries are less toxic than unripe green ones, but they still contain lantadenes. The reduction in toxicity at full ripeness does not make them safe to consume.

Why is lantana especially dangerous to horses and livestock? Grazing animals consume large amounts of plant material over time, which means cumulative lantadene exposure is much higher than what a pet or child would typically receive from a single exposure. Liver damage from lantana in livestock tends to follow repeated grazing rather than a single large dose.

Can I grow lantana in a garden with dogs? It requires caution. If your dog actively chews plants or scavenges fallen berries, lantana is a genuine risk. If your dog ignores garden plants, keeping lantana trimmed to reduce berry development is a reasonable mitigation. Either way, keeping the plant inaccessible is safer.

Is lantana on the ASPCA toxic plant list? Yes. The ASPCA lists lantana as toxic to dogs, cats, and horses, with pentacyclic triterpenoids as the toxic principle and vomiting, diarrhea, labored breathing, weakness, and liver failure (more common in livestock) as the clinical signs.