Is Lily of the valley toxic to cats?

Convallaria majalis · Asparagaceae

Yes. Can kill a cat.

Another heart plant, and not a lily: it does not touch the kidneys, it disturbs the heart's rhythm.

For a cat

Can kill

For a person

Can kill

Lily of the valley in flower, small white bells hanging along a stem above broad leaves — Matti Virtala · CC0 · Wikimedia Commons

If your cat may have eaten this, call now. Do not wait for symptoms.

Your own vet first, and out of hours the nearest emergency clinic. If you cannot reach one, these services answer around the clock:

United States
ASPCA Animal Poison Control Center
(888) 426-4435
24 hours a day, 365 days a year. A consultation fee applies; the ASPCA does not publish the amount.
United States and Canada
Pet Poison Helpline
(855) 764-7661
$89 per incident, covering follow-up calls with you and your vet. Canada has no service of its own: this line and the ASPCA both cover it.
United Kingdom
Animal PoisonLine
01202 509 000
24 hours. £35 from 8am to 8pm on weekdays, £45 at all other times, refunded automatically if your vet then calls the service for treatment advice.
Australia
Animal Poisons Helpline
1300 869 738
24/7. Their own site says consultations are available from $75 AUD, though the RSPCA describes the line as free: check when you call.

Take the plant, or a photo of it, with you. Naming it is what decides the treatment, and a trade label on a pot is often not the plant's real name.

What to watch for

Vomiting
Irregular heart beat
Low blood pressure
Disorientation
Coma
Seizures

Often begins as vomiting and loss of appetite. Heart rhythm changes, weakness and seizures are the signs that the poisoning is not staying in the stomach.

Why, and which parts

All parts, including the water it has stood in.

Toxic principle: Cardenolides (convallarin, and others)

Cardenolides act on the heart exactly as oleander's oleandrin does, by blocking the sodium and potassium pump in heart muscle. The plant's reputation as a harmless spring posy is the danger: it is sold cut, kept in water, and the water it has stood in carries the toxin too.

How to recognize it

Small white bells hanging in a row along one side of a slender stalk, between two broad leaves. Sold as a spring posy.

A dense patch of lily of the valley leaves, broad and upright, before flowering — Borealis55 · CC0 · Wikimedia Commons

Plants it gets confused with

True lily

Only the name is shared. Different plant, different family, different mechanism.

Why it matters: Both are emergencies but the treatment differs: one is a kidney case, the other a cardiac one. Name the plant when you call.

And for a person?

Dangerous to a person too

Dangerous to people too.

A plant's danger to a cat says nothing about its danger to you, and the reverse is just as true. This is a separate question with a separate answer.

This is information, not veterinary advice, and it cannot tell you what is wrong with your cat. Our rule is a simple one: if something is wrong with your cat, call your vet, and call an emergency clinic if it is out of hours. Nothing you read here is a reason to wait.

Lily of the valley: the plant that can kill your cat

Worth keeping a paw on

Pin this profile

To recognize the plant the day you come across it, and warn the friends whose cat goes outside. One click and it sits in your board.

Pin it on Pinterest

Our sources

Other plants at the same level

Same verdict for a cat as Lily of the valley. The ones sharing its exact toxic principle come first.

OleanderNerium oleander

Sago palmCycas revoluta

True lilyLilium spp.

YewTaxus spp.

Every plant, ranked by how dangerous it is