Lily of the Valley

Yes, Lily of the Valley (Convallaria majalis) is highly toxic to cats. It contains cardiac glycosides that can cause life-threatening heart arrhythmias, and ingestion of any part of the plant — flowers, leaves, or roots — is considered a veterinary emergency.

Early signs include vomiting, drooling, and lethargy, typically appearing within 2 hours of exposure. These can rapidly progress to slow or irregular heartbeat, low blood pressure, disorientation, weakness, and in severe cases seizures or collapse. Heart and GI symptoms together after garden access are a major red flag.

Call your vet, the ASPCA Animal Poison Control Center at (888) 426-4435, or the Pet Poison Helpline at (855) 764-7661 immediately — do not wait for symptoms to appear or worsen. Cats with significant exposure typically require ECG monitoring and supportive care, and clinical signs can persist 4–5 days during treatment.

No safe amount is known — ingestion of any part of the plant is considered potentially life-threatening due to its cardiac glycoside content. The severity notes from this plant's toxicity profile explicitly state that any ingestion can lead to life-threatening cardiac arrhythmias.

Yes, Lily of the Valley (Convallaria majalis) is highly toxic to dogs. It contains potent cardiac glycosides that affect the heart muscle, and even small ingestions can cause serious harm. Immediate veterinary intervention is required if your dog consumes any part of this plant.

Symptoms typically begin within 2 hours of ingestion and include vomiting, diarrhea, and lethargy, followed by cardiac rhythm disturbances, slow or irregular heartbeat, weakness, low blood pressure, disorientation, collapse, and possibly seizures. Clinical effects can persist 4–5 days during supportive care.

Call your vet or ASPCA Animal Poison Control at (888) 426-4435 immediately — do not wait to see how symptoms develop at home. Heart monitoring and supportive care are typically required, and severe cases may need digoxin-binding antibody therapy. Time is critical with cardiac glycoside poisoning.

All parts of the plant contain cardiac glycosides and are considered toxic — flowers, leaves, stems, and roots. There is no safe portion to expose your dog to, so the entire plant should be kept out of reach.