Last updated: May 16, 2026

Are Lily of the Valley Toxic to Dogs? A Deadly Danger Hiding in Plain Sight

With its dainty, bell-shaped white flowers and sweet fragrance, lily of the valley (Convallaria majalis) looks like the picture of innocence. It carpets shady garden beds with elegant green leaves and nodding flower stalks each spring, and it has long been associated with purity, happiness, and the return of warm weather. But behind that charming exterior lies one of the most dangerous plants a dog can encounter.

Lily of the valley is very toxic to dogs. Every part of this plant — the flowers, leaves, stems, roots, and even the red berries that appear in late summer — contains potent cardiac glycosides that can disrupt your dog’s heart rhythm and, in severe cases, cause fatal cardiac arrest. This is not a plant that causes a little stomach upset. This is a plant that veterinary toxicologists take extremely seriously, and so should you.

The Deadly Chemistry of Lily of the Valley

Lily of the valley contains more than 30 different cardiac glycosides, making it one of the most glycoside-rich plants known. The primary toxic compounds include convallatoxin, convallamarin, and convallarin, with convallatoxin being the most potent. These compounds are structurally and functionally similar to digoxin, the cardiac medication derived from foxglove, and they act on the heart through the same mechanism.

Cardiac glycosides work by inhibiting the sodium-potassium ATPase pump in cardiac muscle cells. This enzyme is essential for maintaining the normal electrical gradient across heart cell membranes, which in turn is essential for the heart to beat in a coordinated, rhythmic fashion. When the pump is blocked, intracellular calcium levels rise, sodium-potassium balance is disrupted, and the heart’s electrical system becomes increasingly unstable.

The result is a cascade of cardiac dysfunction that can progress from mild rhythm disturbances to complete cardiovascular collapse. The heart may beat too slowly (bradycardia), too irregularly (various arrhythmias), or eventually stop altogether. The potency of these compounds is remarkable — convallatoxin is considered one of the most toxic naturally occurring cardiac glycosides, more potent per milligram than the digoxin derived from foxglove.

What makes lily of the valley particularly insidious is that the toxins are present in exceptionally high concentrations throughout the entire plant. The leaves and flowers contain the highest levels, but the roots and berries are also significantly toxic. The water in a vase that held cut lily of the valley can contain enough dissolved glycosides to poison a small dog who drinks from it. Even touching the plant and then putting hands (or paws) to mouth can transfer enough toxin to cause concern.

The toxins are also remarkably stable. Dried lily of the valley retains its toxicity, and even composted or decomposing plant material can remain dangerous. There is no safe way to handle or store this plant in a dog-accessible environment.

Symptoms of Lily of the Valley Poisoning in Dogs

The symptoms of lily of the valley poisoning can develop within one to several hours after ingestion and tend to follow a progressive pattern from gastrointestinal distress to cardiovascular crisis. The timeline depends on how much was consumed, but even small amounts can cause symptoms, and owners should not wait for “enough” to happen before seeking help.

The earliest symptoms are usually gastrointestinal: drooling, nausea, vomiting, abdominal pain, and diarrhea. The vomiting may be forceful and repeated, and the diarrhea may be watery or contain blood. These GI symptoms reflect the direct irritant effects of the glycosides on the stomach and intestinal lining, as well as the systemic effects of the toxin on the body’s vagal tone.

As the cardiac glycosides are absorbed into the bloodstream, the more dangerous cardiovascular symptoms begin. These include a dramatically slowed heart rate (bradycardia) — the heart may be beating so slowly that it is easily perceptible even to an untrained observer. Irregular heartbeat (arrhythmias) of various types can develop, ranging from skipped beats to chaotic, life-threatening rhythms. Blood pressure drops, leading to weakness, dizziness, and collapse.

Neurological symptoms often accompany the cardiac effects and may include dilated pupils, confusion or disorientation, depression and lethargy, tremors, and in severe cases, seizures. Visual disturbances have been documented in other species with cardiac glycoside poisoning, though these are difficult to confirm in dogs.

One of the hallmarks of severe cardiac glycoside poisoning is hyperkalemia — dangerously elevated potassium levels in the blood. This occurs because the sodium-potassium pump that the glycosides are blocking is responsible for maintaining potassium balance. Rising potassium further destabilizes the heart rhythm and creates a vicious cycle where the cardiac effects of the glycosides are compounded by the cardiac effects of high potassium. This is why blood work and electrolyte monitoring are critical components of treatment.

In the most severe cases, lily of the valley poisoning can progress to complete heart block, ventricular fibrillation, and death. This can happen within hours of ingestion, which is why immediate veterinary care is absolutely essential.

Emergency Response: Every Minute Matters

If you have any reason to believe your dog has eaten any part of a lily of the valley plant — or has had access to water from a vase containing these flowers — treat it as a life-threatening emergency. The window for effective intervention is narrow, and delay can be fatal.

Immediately remove your dog from the area and prevent further access to the plant. Check your dog’s mouth for any remaining plant material and gently remove what you can. Try to estimate what was eaten: Was it a leaf? Multiple leaves? Flowers? Berries? How long ago do you think it happened?

Call your veterinarian or an emergency animal hospital right away. If you cannot reach your regular vet, call the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661. These services can provide immediate guidance and will typically alert your local emergency clinic about the incoming case.

Do not wait for symptoms to develop. With cardiac glycoside poisoning, the time between “my dog seems fine” and “my dog is in cardiac crisis” can be terrifyingly short. It is far better to rush to the vet and discover the situation was less serious than feared than to wait and arrive too late for effective treatment.

Do not induce vomiting at home unless a veterinary professional specifically instructs you to do so. While early emesis can be very beneficial, the decision requires professional judgment about your dog’s cardiovascular status. If cardiac effects are already developing, the stress and vagal stimulation associated with vomiting can worsen arrhythmias.

During transport, keep your dog as calm and still as possible. Avoid carrying them against your chest where they can feel your own anxiety. Place them securely in the car and drive directly to the nearest emergency veterinary facility. For a comprehensive guide on managing these emergencies, see our pet poisoning emergency article. If your dog has also been around other types of lilies, note that lily toxicity in dogs varies by species — true lilies pose different risks than lily of the valley.

Veterinary Treatment: Intensive Care for a Serious Toxin

Treatment for lily of the valley poisoning requires intensive veterinary care, often including hospitalization for 24 to 72 hours or longer. The treatment protocol focuses on three pillars: decontamination, cardiac stabilization, and electrolyte management.

If the dog presents within one to two hours of ingestion and cardiac rhythm is stable, the veterinarian will likely induce vomiting to remove as much plant material from the stomach as possible. Following emesis, activated charcoal is administered — and this is a case where repeated doses of activated charcoal are particularly important, because cardiac glycosides undergo enterohepatic recirculation. This means the toxins are excreted from the liver into the bile, re-enter the intestines, and can be reabsorbed, extending and potentially worsening the poisoning. Multiple doses of activated charcoal over 24 hours can help interrupt this cycle.

Continuous electrocardiographic (ECG) monitoring is essential throughout treatment. The veterinary team will watch for characteristic glycoside-induced arrhythmias and treat them as they arise. Atropine is the first-line drug for severe bradycardia. Lidocaine or other anti-arrhythmic medications may be used for ventricular arrhythmias. The specific treatment is tailored to the specific rhythm disturbance, which can change over the course of the poisoning.

Intravenous fluid therapy is standard to support blood pressure, maintain adequate organ perfusion, and assist in toxin elimination through the kidneys. Electrolyte levels, particularly potassium, are monitored frequently — often every few hours — and corrected as needed. If hyperkalemia develops, specific treatments including insulin-glucose infusions, sodium bicarbonate, or calcium gluconate may be used to protect the heart while lowering potassium levels.

In severe cases, the gold standard treatment is digoxin-specific antibody fragments, commercially known as Digibind or DigiFab. Originally developed for human digitalis overdose, these antibodies bind to cardiac glycosides in the bloodstream and neutralize them. They have been used successfully in dogs with lily of the valley poisoning and can produce dramatic improvement even in critically ill patients. The main barriers to their use are cost (a full course can be thousands of dollars) and availability (they are primarily stocked in human hospital pharmacies). If your dog’s case is severe, your veterinarian may be able to source these antibodies from a nearby human hospital.

The prognosis depends on the amount ingested, the speed of treatment, and the severity of cardiac involvement at the time of presentation. Dogs who receive early decontamination before significant cardiac symptoms develop generally have a good prognosis. Dogs who present with established, severe arrhythmias face a more guarded outlook but can still recover with aggressive care. The first 24 hours are the most critical — if a dog survives this period with stable cardiac rhythms, the prognosis improves significantly.

Prevention: Keeping Lily of the Valley Away from Dogs

Given the extreme toxicity of lily of the valley, prevention is not just important — it is essential. Here are concrete steps to protect your dog:

Remove lily of the valley from your property if you have dogs. This is the single most effective prevention measure. Lily of the valley spreads aggressively through underground rhizomes and can be difficult to eradicate completely, but persistent removal over one to two growing seasons can usually eliminate it. Dig up the plants, including as much of the root system as possible, and dispose of all plant material in sealed bags — not in compost that dogs might access.

Never bring cut lily of the valley flowers into a home with dogs. Even a small bouquet in a vase on a table can be a hazard if a dog can reach the flowers or drink the vase water. If you receive lily of the valley as a gift, keep it in a completely dog-proof room or, better yet, enjoy it at the office instead.

Be aware of where lily of the valley grows in your neighborhood, local parks, and hiking areas. It thrives in shady, moist conditions and can form dense colonies under trees, along north-facing foundations, and in woodland gardens. When walking your dog in these areas, keep them on leash and redirect their attention away from any lily of the valley patches.

Watch out for the berries. In late summer and fall, lily of the valley produces small, round, bright red-orange berries that can be particularly attractive to curious dogs. These berries are highly toxic and, because they are colorful and at nose level, may be more tempting than the leaves and flowers.

Safer groundcover alternatives to lily of the valley include sweet woodruff (Galium odoratum), creeping thyme, Irish moss (Sagina subulata), or various sedges and native ground covers that can fill the same ecological niche without the toxicity risk. For more options, browse our pet-safe garden plants guide.

Lily of the Valley vs. Other “Lilies”: An Important Distinction

The common name “lily” causes significant confusion among pet owners because it is applied to many unrelated plants with very different toxicity profiles. It is important to understand that lily of the valley is not a true lily — it belongs to the family Asparagaceae, not Liliaceae — and its toxic mechanism is entirely different from that of true lilies.

True lilies (Lilium species) such as Easter lilies, Asiatic lilies, and daylilies are extremely dangerous to cats because they can cause acute kidney failure, but they are generally considered much less toxic to dogs. Lily of the valley, on the other hand, is dangerous to dogs AND cats, and its threat comes from cardiac glycosides rather than kidney toxins.

Other “lilies” that are also unrelated but use the common name include peace lilies (Spathiphyllum), which contain calcium oxalate crystals and cause oral irritation, calla lilies (Zantedeschia), which also contain calcium oxalates, and canna lilies, which are generally non-toxic. Each of these has its own risk profile, and confusing them can lead to either unnecessary panic or, worse, dangerous complacency.

The takeaway is simple: if your dog eats anything called a “lily,” do not assume it is safe or try to self-diagnose. Call your vet or poison control immediately and let the professionals assess the risk based on the specific plant involved. A clear photo or a sample of the plant can help enormously with rapid identification.

Frequently Asked Questions

Can a dog die from eating lily of the valley?

Yes. Lily of the valley is one of the most toxic common garden plants, and fatal poisoning in dogs has been documented. The cardiac glycosides in this plant can cause lethal heart arrhythmias and cardiac arrest. The risk of death is highest when treatment is delayed, when a large amount is consumed, or when the dog is small relative to the dose. However, with early and aggressive veterinary treatment, many dogs can and do survive lily of the valley poisoning.

How much lily of the valley is dangerous for a dog?

Even small amounts can be dangerous, particularly for smaller dogs. There is no well-established “safe” threshold — the cardiac glycosides in lily of the valley are potent enough that even a few chewed leaves can potentially cause cardiac symptoms in a small dog. A single leaf may cause gastrointestinal upset without serious cardiac effects, but this depends on the leaf size, glycoside concentration, and the individual dog’s sensitivity. Never try to estimate whether “enough” was eaten — treat any ingestion as an emergency.

Is the water from a lily of the valley vase dangerous to dogs?

Yes. Cardiac glycosides leach from the stems and flowers into the water, and the resulting solution can contain enough toxin to cause poisoning in a small dog who drinks from the vase. This is a commonly overlooked exposure risk. If you have cut lily of the valley flowers in your home, ensure the vase is completely inaccessible to pets, and dispose of the water carefully — do not pour it into a pet’s water bowl or anywhere a pet might drink from.

Is lily of the valley toxic to cats too?

Yes. Lily of the valley is toxic to cats, dogs, horses, and many other animals. The cardiac glycosides affect all mammalian hearts through the same mechanism. Cats who ingest lily of the valley face the same risks of cardiac arrhythmias and potential cardiac arrest as dogs. If you have cats, lily of the valley should be treated with the same level of extreme caution.

What plants can I use instead of lily of the valley in shady areas?

Several beautiful, dog-safe groundcovers thrive in the same shady, moist conditions that lily of the valley prefers. Sweet woodruff produces delicate white flowers and fragrant foliage. Wild ginger (Asarum) offers glossy, heart-shaped leaves. Various ferns, including Christmas fern and maidenhair fern, are non-toxic and provide lush texture in shade gardens. Ajuga (bugleweed) is a fast-spreading groundcover with purple flowers that is generally considered safe for dogs. These alternatives can fill the same garden niche without the cardiac glycoside danger.