How to Identify Toxic Plants for Dogs and Cats
A surprising number of common houseplants — including ones sold at every Home Depot and Whole Foods garden section — are toxic to dogs and cats. Some cause mild stomach upset; a few are dangerous enough to require an emergency vet visit. This guide covers the plants worth memorizing, how to identify one if you're not sure, and what to do if your pet eats something it shouldn't.
⚠️ If your pet just ate a plant
Call your vet or the ASPCA Animal Poison Control Center: (888) 426-4435. There's a $95 consultation fee but they're available 24/7 and they have the most complete database of plant toxicology for pets. Don't wait to see if symptoms develop — early treatment matters.
For dogs: Pet Poison Helpline is (855) 764-7661. For UK readers: Animal PoisonLine (01202 509000).
The 10 most common toxic plants you probably have
Severe toxicity: Lilies (cats), Sago Palm, Oleander, Dieffenbachia
Moderate: Pothos, Philodendron, Monstera, Peace Lily, ZZ Plant, English Ivy
Symptoms to watch for: drooling, vomiting, loss of appetite, lethargy, mouth pawing, difficulty breathing
The big ones: severe-toxicity plants
If you have a cat or dog, these are the plants worth removing from your home or putting in a room your pet can't access.
Lilies (Lilium and Hemerocallis species)
True lilies — Easter Lily, Tiger Lily, Asiatic Lily, Daylily — are extremely toxic to cats. Eating any part of the plant, drinking water from a vase with cut lilies, or even grooming pollen off their fur can cause acute kidney failure within 24-72 hours. The mortality rate is significant even with prompt treatment.
Cut lilies in bouquets are responsible for many cat poisoning cases — owners don't realize the danger. Don't keep lilies in any house with cats.
How to identify: Trumpet-shaped flowers with 6 petals, usually large (3-8 inches). Strong fragrance. Pollen-heavy yellow stamens. Leaves are long, narrow, and arranged alternately on a tall stem.
Sago Palm (Cycas revoluta)
Sago Palm is one of the most dangerous plants for both dogs and cats. The seeds are the most toxic part but the entire plant contains cycasin, a liver toxin. Death rate without treatment is approximately 50%.
How to identify: Despite the name, it's a cycad, not a true palm. Short trunk with a crown of stiff, dark green, feather-like leaflets arranged in a circular pattern. Often sold as a small "ornamental palm" in pots.
Oleander (Nerium oleander)
Common as an outdoor ornamental shrub in warm climates (California, Florida, Mediterranean). All parts are toxic — even smoke from burning oleander is dangerous. Causes cardiac arrhythmia.
How to identify: Evergreen shrub or small tree. Narrow, lance-shaped leaves in whorls of 3. Flowers in clusters at branch tips, usually pink, white, or red, with 5 petals.
Dieffenbachia (Dumb Cane)
Calcium oxalate crystals cause intense mouth pain, swelling of the tongue, and in severe cases, the throat can swell enough to obstruct breathing. The common name "Dumb Cane" comes from the loss of speech caused by mouth swelling.
How to identify: Large oval leaves, dark green with cream or yellow variegated patterns. Grows upright on a single thick stem.
Moderate toxicity: common houseplants pet owners get wrong
These won't kill your pet from one nibble, but they cause real discomfort and you should still keep them out of reach. They're worth identifying because they're frequently mistaken for safer species.
Pothos (Epipremnum aureum)
Probably the most popular houseplant in North America. Calcium oxalate crystals cause oral irritation, drooling, vomiting, and difficulty swallowing.
Frequently confused with: Philodendron (also toxic). Real distinguishing feature: Pothos has a thicker, waxier leaf and the leaf base is more symmetric.
Philodendron (multiple species)
Same toxin family as Pothos — calcium oxalate. Same symptoms.
How to identify: Heart-shaped, glossy leaves that come to a point. Often confused with Pothos but Philodendron leaves are typically thinner, more matte, and the base is more asymmetric (one lobe is smaller).
Monstera deliciosa (Swiss Cheese Plant)
Calcium oxalate again. The fruit, when ripe, is actually edible — but the leaves and stems cause mouth irritation, drooling, and stomach upset.
How to identify: Large, glossy, heart-shaped leaves with the iconic deep splits and oval holes ("fenestrations") that develop as the plant matures.
Peace Lily (Spathiphyllum)
Despite the name, Peace Lily is not a true lily — it's not in the deadly Lilium family. But it does contain calcium oxalate and causes oral irritation, drooling, and vomiting.
How to identify: Dark green, lance-shaped leaves rising directly from the soil. White single-petal "flower" (actually a modified leaf called a spathe) surrounding a yellow spike.
ZZ Plant (Zamioculcas zamiifolia)
Resilient houseplant favorite. All parts contain calcium oxalate. Symptoms include drooling, vomiting, and pawing at the mouth.
How to identify: Glossy, dark green, oval-shaped leaflets arranged along stiff stalks rising from a thick rhizome.
English Ivy (Hedera helix)
Trailing vine sold for indoor pots and outdoor ground cover. Contains saponins and polyacetylene compounds that cause vomiting, diarrhea, and excessive salivation.
How to identify: Climbing or trailing vine with classic lobed, ivy-shaped leaves. Mature plants may produce small greenish flowers and black berries (also toxic).
Common confusions: similar-looking plants, very different toxicity
The trickiest part of plant toxicity isn't memorizing names — it's that many toxic and non-toxic plants look very similar. A few of the most common mix-ups:
- Spider Plant (Chlorophytum comosum, safe) vs Snake Plant (Dracaena trifasciata, mildly toxic). Both have long, sword-like leaves rising from the base. Snake Plant leaves are stiffer, thicker, and have horizontal banding. Spider Plant leaves arch and produce baby "spiderettes" on long stems.
- Boston Fern (safe) vs Asparagus Fern (toxic). Boston Fern has soft, arching fronds with regular leaflets. Asparagus Fern (which isn't a true fern) has needle-like leaves that look fluffy and feathery.
- True Aloe (Aloe vera, mildly toxic) vs Haworthia (safe). Both are succulents with thick, pointed rosettes. Aloe is larger and the leaves are smoother. Haworthia leaves have raised white horizontal stripes.
- Calathea (safe) vs Maranta vs Stromanthe (all in same family, all safe). All "prayer plants" with patterned leaves. Variations in pattern, but all three are pet-safe.
How to identify a plant before it goes near your pet
If you're not sure what a plant is — whether it's a gift, an inherited houseplant, or a wildflower in your yard — identify it before letting your pet anywhere near it. Three options:
- Use a plant identification app. Nature Lenz includes a check for known pet toxicity in the care guide for each identified plant. PictureThis and the free alternatives all do identification well; the question is whether they show toxicity prominently.
- Cross-reference the ASPCA toxic plants database. Their list (aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants) is the gold standard. Search by plant name once you have an ID.
- If in doubt, treat it as toxic. Don't take chances. Most apps will give you a confidence score with their identification — if confidence is below 85%, assume the wrong species and act conservatively.
What to do if your pet eats a toxic plant
- Identify what they ate. Take a photo of the plant for the vet. If part of the plant is missing, see if you can identify which species.
- Call ASPCA Animal Poison Control: (888) 426-4435 or Pet Poison Helpline: (855) 764-7661. They will tell you whether you need an emergency vet visit.
- Do NOT induce vomiting unless instructed by a vet. Some plant toxins (especially calcium oxalate) cause more damage on the way back up than down.
- Bring the plant or a photo to the vet. Treatment is far more effective when the vet knows exactly what the toxin is.
- Watch for delayed symptoms. Some plants (notably lilies in cats) show no symptoms for 12-24 hours, then cause sudden kidney failure. Don't wait it out.
Pet-safe plants you can keep instead
If you're rebuilding your plant collection around your pet, here are common houseplants that are confirmed safe for both dogs and cats:
- Spider Plant (Chlorophytum comosum)
- Boston Fern (Nephrolepis exaltata)
- Calathea / Prayer Plant (Maranta, Calathea, Stromanthe)
- African Violet (Saintpaulia ionantha)
- Money Tree (Pachira aquatica)
- Areca Palm (Dypsis lutescens) — true palm, safe
- Bamboo Palm (Chamaedorea seifrizii)
- Polka Dot Plant (Hypoestes phyllostachya)
- Haworthia (succulent, looks like aloe but safe)
Identify any plant before it reaches your pet
Nature Lenz identifies plants and flags pet toxicity in the care guide for each. Free, no paywall, available on iOS.
Get the app →FAQs
Is Monstera toxic to cats?
Yes, mildly to moderately. Monstera deliciosa contains calcium oxalate crystals, which cause mouth pain, drooling, vomiting, and pawing at the mouth in cats. Symptoms are unpleasant but rarely life-threatening. Keep out of reach.
Are succulents safe for cats?
Most are, but not all. Aloe vera is mildly toxic. Jade Plant (Crassula ovata) is toxic. Echeveria, Haworthia, and Sedum are generally safe. When in doubt, identify the specific species before assuming "succulent = safe."
Are orchids safe for cats and dogs?
Most common orchids (Phalaenopsis, Dendrobium, Cattleya) are non-toxic to dogs and cats. ASPCA lists Phalaenopsis as safe. The pesticides used on commercial orchids are a bigger risk than the plant itself — wash thoroughly before bringing home.
What about cut flowers in a vase?
Lilies in vases are the #1 cause of cat poisoning from cut flowers. Even drinking the water can be deadly. Other cut flowers to keep out of pet reach: chrysanthemums, daffodils, tulips, hyacinths.
My dog ate a Pothos leaf. Should I rush to the vet?
Call ASPCA Animal Poison Control first: (888) 426-4435. For Pothos, the answer is often "monitor for drooling, vomiting, and decreased appetite; come in if symptoms persist or worsen." But it depends on dose and your dog's size. Always get professional advice rather than waiting it out.