Dr. Tiffany Delacruz, DVM • Chief Executive Officer, RexVet • 2026-06-09 • 10 min read
Poisonous Plants for Dogs and Cats: The 2026 Reference
Common house and garden plants that are toxic to dogs and cats — lilies, sago palm, dieffenbachia, azaleas, and more. Symptoms, severity tiers, and emergency steps, vet-authored.
Medically reviewed by Dr. Tiffany Delacruz, DVM
Most pet plant exposures cause mild GI upset and self-resolve. A short list of plants cause severe, sometimes fatal poisonings — and these are exactly the plants most commonly given as gifts, planted ornamentally, or kept indoors. This guide tiers plants by severity so you know which are emergencies and which are mild.
Tier 1: Potentially fatal plants
Any exposure to a Tier 1 plant warrants an immediate vet call. Do not wait for symptoms.
Lilies (cats — kidney failure)
Every plant in the Lilium (true lilies) and Hemerocallis (daylilies) genera causes acute kidney failure in cats. Includes: Easter lily, tiger lily, Asiatic lily, Japanese show lily, day lily. A single petal, leaf, or even pollen ingested during grooming can be fatal. Dogs are not affected — but if you have both species in the house, remove the lily. There is no antidote; treatment is aggressive IV fluids and supportive care, and prognosis depends on speed of intervention.
Sago palm (dogs and cats — liver failure)
All parts of the sago palm (Cycas revoluta) contain cycasin, which causes severe liver failure. The seeds are most toxic, but leaves, bark, and roots are all dangerous. Mortality is around 50% even with aggressive treatment. Common as a landscape plant in warm climates (FL, CA, TX) and increasingly popular as a house plant.
Yew (cardiac arrest)
Common evergreen shrub (Taxus species) used in landscaping. All parts except the red flesh of the berry contain taxine alkaloids that cause cardiac arrest. Often eaten by dogs or curious cats who chew on landscape plants. There is no specific antidote.
Oleander (cardiac toxicity)
All parts of oleander (Nerium oleander) contain cardiac glycosides similar to digitalis. Common landscape plant in warm climates. Causes vomiting, slow or irregular heart rate, weakness, and potentially fatal cardiac arrhythmia.
Foxglove (cardiac toxicity)
Similar cardiac glycoside profile to oleander. Garden ornamental. All parts toxic, including dried plant material.
Tier 2: Serious toxicity
Tier 2 plants cause significant illness; most pets recover with prompt treatment but supportive care is often hospital-level.
Azaleas and rhododendrons
Common landscape shrubs. Contain grayanotoxins that cause vomiting, drooling, weakness, and (in larger doses) heart rhythm disturbances and collapse.
Tulip and hyacinth bulbs
The bulb is the most toxic part — much more than the flower or leaves. Dogs that dig up planted bulbs or eat fallen ones can develop severe GI signs.
Cyclamen
Popular winter house plant. The tubers (underground) are most toxic. Causes severe vomiting and diarrhea; large ingestions can be fatal.
Castor bean (Ricinus communis)
Contains ricin. Even small amounts can be lethal. Used ornamentally in some warm climates.
English ivy and devil's ivy (pothos)
Extremely common house plants. Cause oral irritation and GI upset; severe ingestions occasionally require veterinary intervention.
Tier 3: Mild to moderate toxicity
Tier 3 plants typically cause oral irritation or mild GI signs. Most pets recover at home, but a vet call is appropriate if signs are pronounced.
Dieffenbachia (dumb cane)
Calcium oxalate crystals cause oral pain, drooling, and difficulty swallowing. Rarely fatal but uncomfortable for hours.
Philodendron
Same oxalate-crystal mechanism as dieffenbachia.
Peace lily (Spathiphyllum) — note: NOT a true lily
Despite the name, peace lily is not in the toxic Lilium/Hemerocallis genera. It causes oral irritation similar to dieffenbachia but is not associated with the acute kidney failure that defines true lily toxicity.
Aloe vera
Mild laxative effect in pets. Most home exposures are minor. The latex (yellow layer just under the skin) is the more irritating part.
Poinsettia (overrated as a danger)
Famously labeled as toxic, but in reality causes only mild oral irritation and drooling. Holiday gift plant; rarely an emergency.
Pet-safe house plants
Verified non-toxic options if you have curious pets:
- Boston fern (Nephrolepis exaltata)
- Spider plant (Chlorophytum comosum)
- African violet (Saintpaulia)
- Areca palm (Dypsis lutescens) — different from sago palm; this one is safe
- Christmas cactus (Schlumbergera)
- Echeveria succulents
- Phalaenopsis orchid
- Calathea varieties
- Money tree (Pachira aquatica)
Cross-references and confirmation
ASPCA's Toxic and Non-Toxic Plants list (aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants) is the authoritative reference — searchable by plant name. Pet Poison Helpline maintains a similar database. When in doubt about a specific plant, look it up there before buying.
Emergency signals
When to contact a veterinarian
- Any exposure to a Tier 1 plant (lilies for cats; sago palm, yew, oleander, foxglove)
- Visible drooling, oral pain, or refusal to eat after plant exposure
- Vomiting, lethargy, or weakness after access to a garden or houseplant
- Pale gums, bloody urine, or jaundice in the days after exposure
- Any abnormal heart rate or breathing after exposure
Frequently asked questions
What plants are most dangerous to cats?
Lilies (any species of Lilium or Hemerocallis) are the most dangerous plant to cats — a single petal can cause acute kidney failure. Other high-risk plants for cats: sago palm (liver failure), yew (cardiac arrest), oleander (cardiac toxicity), foxglove, and castor bean. If you have a cat, do not keep lilies in your home.
What plants are most dangerous to dogs?
Sago palm is the most dangerous common plant for dogs — all parts cause severe liver failure with about 50% mortality even with treatment. Other high-risk plants for dogs: yew, oleander, foxglove, castor bean, azalea, rhododendron, tulip and hyacinth bulbs. Many of these are common landscape plants.
Are peace lilies toxic to cats?
Peace lilies (Spathiphyllum) are misleadingly named — they are NOT in the toxic Lilium/Hemerocallis genera. They cause oral irritation and drooling from calcium oxalate crystals, but they do NOT cause the acute kidney failure that defines true lily toxicity. Still avoid if your cat chews plants, but they're not a fatal-on-exposure plant.
Are poinsettias really poisonous to pets?
Poinsettias have a famously exaggerated reputation. They cause only mild oral irritation and drooling — rarely a true emergency. The holiday gift plant is much less dangerous than its reputation suggests. Lilies, sago palm, and yew are far more important plants to keep away from pets.
What should I do if my pet ate a poisonous plant?
Identify the plant if possible (photo, label, sample). Call a pet poison hotline (1-855-764-7661 or 1-888-426-4435) or your nearest 24-hour emergency clinic. Bring the plant or a photo with you. For Tier 1 plants (lilies, sago palm, yew, oleander, foxglove), do not wait for symptoms — go directly to the emergency clinic.