If you have ever asked whether spider plants are toxic to cats, the answer is no — but many other popular houseplants are. We have compiled the 14 most dangerous plants for pets, covering the full spectrum from mild mouth irritation to life-threatening organ failure.
URGENT: If you suspect your pet has ingested any toxic plant, contact your veterinarian immediately or call the ASPCA Animal Poison Control Center at (888) 426-4435.
TL;DR — Fast Facts
- Pothos — Causes oral burning and vomiting in cats and dogs
- Monstera Deliciosa — Triggers mouth and throat irritation
- Peace Lily — Leads to drooling and oral discomfort
- ZZ Plant — Contains crystals that irritate mouth and stomach
- Snake Plant — Causes mild to moderate gastrointestinal upset
- Aloe Vera — Provokes vomiting, diarrhea, and tremors
- Jade Plant — Induces vomiting, depression, and wobbliness
- Dieffenbachia — Causes severe mouth swelling and breathing difficulty
- English Ivy — Triggers severe vomiting and abdominal pain
- Tulip and Daffodil Bulbs — Can cause cardiac arrhythmias and convulsions
- Azalea and Rhododendron — May lead to coma or death in small pets
- Sago Palm — Causes liver failure with a high mortality rate
- Oleander — Potentially fatal cardiac toxin for all pets
- Lilies — Fatal kidney failure in cats; no safe exposure level
How We Evaluated
This list was assembled using veterinary toxicity classifications from the ASPCA Animal Poison Control Center and Pet Poison Helpline, cross-referenced with frequency of household ownership in the UK and Australia. Plants were ranked by clinical severity. We prioritized species that are both commonly kept indoors and pose documented risks to cats and dogs.
1. Pothos (Epipremnum aureum): Oral Irritation and Vomiting
Pothos is one of the most common houseplants in the world — and one of the most frequent culprits in pet poisoning calls. The leaves and stems contain insoluble calcium oxalate crystals that embed themselves in soft mouth tissue when chewed.
A cat or dog that bites into a pothos leaf will experience immediate burning, excessive drooling, and pawing at the mouth. Vomiting usually follows within minutes to hours. While pothos toxicity is rarely fatal, the pain can be severe enough to cause temporary refusal to eat or drink. All parts of the pothos plant contain calcium oxalate crystals that trigger immediate oral burning and vomiting in both cats and dogs.
Symptoms to watch for: Drooling, pawing at the mouth, vomiting, and decreased appetite within 1-4 hours of exposure.
Safer swap: Replace pothos with a spider plant or Boston fern — both are non-toxic and equally forgiving for beginner plant parents.
2. Monstera Deliciosa (Monstera deliciosa): Mouth and Throat Irritation
The Monstera Deliciosa is an interior design staple, but the entire plant except the ripe fruit carries insoluble calcium oxalate crystals. When a pet chews the leaves, those microscopic needles penetrate the gums, tongue, and throat lining.
Symptoms appear almost immediately: intense drooling, repeated swallowing, and visible discomfort. In rare cases where a large amount is swallowed, swelling can narrow the airway and make breathing difficult. Every part of the Monstera plant except fully ripe fruit contains calcium oxalate crystals that cause immediate oral irritation and swelling.
Symptoms to watch for: Excessive drooling, difficulty swallowing, vomiting, and oral swelling within minutes of ingestion.
Safer swap: A parlor palm or areca palm delivers a similar tropical aesthetic without the risk to curious pets.
3. Peace Lily (Spathiphyllum): Drooling and Oral Burn
Peace lilies are not true lilies — they belong to the Araceae family — but they still pose a genuine threat to pets. Like pothos and Monstera, they contain calcium oxalate crystals that cause immediate tissue irritation when chewed.
A cat that nibbles a peace lily leaf will drool heavily, paw at its mouth, and may vomit repeatedly. The burning sensation can last for hours and may cause the animal to avoid food and water until the irritation subsides. Peace lilies trigger severe oral burning and drooling in cats and dogs, though they do not cause the fatal kidney failure associated with true lilies.
Symptoms to watch for: Heavy drooling, oral pawing, vomiting, and reluctance to eat within 1-2 hours of contact.
Safer swap: An orchid or African violet offers elegant white blooms without any toxicity risk to pets.
4. ZZ Plant (Zamioculcas zamiifolia): Calcium Oxalate Crystals
The ZZ Plant is celebrated for surviving low light and neglect, yet all parts of the plant contain calcium oxalate crystals. These compounds are a defense mechanism against herbivores in the plant’s native East African habitat.
When ingested, the crystals cause immediate burning and swelling of the mouth, tongue, and lips. Pets may also experience vomiting and diarrhea if they swallow leaf material. The sap can irritate human skin during pruning, so wear gloves when handling. The ZZ Plant stores calcium oxalate crystals in every leaf and stem, causing oral burns and gastrointestinal upset in pets that chew the foliage.
Symptoms to watch for: Mouth irritation, swelling of lips or tongue, vomiting, and diarrhea within 2-6 hours.
Safer swap: A cast iron plant or parlor palm tolerates the same low-light conditions and poses no threat to pets.
5. Snake Plant (Dracaena trifasciata): Mild to Moderate Gastrointestinal Upset
Snake plants, formerly classified as Sansevieria, contain saponins — bitter-tasting compounds that deter animals from eating them. Most pets spit out the material after the first bite, which limits the severity of poisoning.
When enough is swallowed, saponins irritate the stomach lining and cause nausea, vomiting, and diarrhea. Symptoms are usually self-limiting and resolve within 24 hours, but dehydration can become a concern if vomiting persists. Snake plants contain saponins that cause mild to moderate vomiting and diarrhea in cats and dogs, with symptoms typically resolving within a day.
Symptoms to watch for: Nausea, vomiting, diarrhea, and loss of appetite within 4-8 hours of ingestion.
Safer swap: A spider plant or Boston fern provides the same vertical architectural interest without saponin toxicity.
6. Aloe Vera (Aloe barbadensis miller): Vomiting and Tremors
Aloe vera gel is safe for human skin, but the latex layer just beneath the skin contains anthraquinone glycosides that act as powerful laxatives. In pets, these compounds trigger a cascade of symptoms that extend well beyond diarrhea.
Cats and dogs that ingest aloe leaves may vomit repeatedly, develop tremors from electrolyte imbalance, and show signs of lethargy or depression. The urine may turn reddish-brown as the kidneys process the compounds. Aloe vera latex contains anthraquinone glycosides that cause vomiting, tremors, and reddish urine in cats and dogs.
Symptoms to watch for: Vomiting, diarrhea, tremors, lethargy, and darkened urine within 6-12 hours.
Safer swap: Haworthia mimics the rosette shape and succulent texture of aloe and is classified as non-toxic to pets.
7. Jade Plant (Crassula ovata): Vomiting and Depression
Jade plants are beloved for their thick, glossy leaves and tree-like growth habit, yet the precise toxin responsible for pet poisoning remains unidentified. Veterinarians recognize the clinical syndrome even though the active compound has not been isolated.
Affected pets show vomiting, depression, and ataxia — a wobbly, uncoordinated gait that resembles intoxication. Some cases involve a slowed heart rate. Symptoms can persist for 24-48 hours depending on the amount consumed. Jade plants cause vomiting, depression, and uncoordinated movement in pets, with symptoms lasting up to 48 hours.
Symptoms to watch for: Vomiting, lethargy, wobbliness, and slow heartbeat within 4-12 hours of ingestion.
Safer swap: Echeveria offers a similar succulent rosette form and is considered safe for both cats and dogs.
8. Dieffenbachia (Dumb Cane): Severe Mouth Swelling
Dieffenbachia contains a high concentration of calcium oxalate crystals alongside proteolytic enzymes that amplify tissue damage. The combination produces more severe reactions than most other arid-family houseplants.
A pet that chews dieffenbachia leaves may experience intense oral burning, dramatic swelling of the tongue and throat, and difficulty breathing if the airway becomes compromised. Vomiting is common, and the pain can be severe enough to cause temporary vocal cord paralysis in extreme cases. Dieffenbachia contains both calcium oxalate crystals and tissue-damaging enzymes that can swell the tongue and throat enough to obstruct breathing.
Symptoms to watch for: Intense drooling, tongue swelling, difficulty breathing, vomiting, and pawing at the face within minutes.
Safer swap: A prayer plant or peperomia provides patterned foliage with zero toxicity risk to pets.
9. English Ivy (Hedera helix): Severe Gastrointestinal Distress
English ivy is a classic trailing plant for shelves and hanging baskets, but the leaves contain triterpenoid saponins that wreak havoc on the digestive systems of cats and dogs.
Ingestion causes severe vomiting, diarrhea, and abdominal cramping. The sap can also irritate the skin and mucous membranes on contact, causing redness and itching around the mouth or paws. English ivy leaves contain triterpenoid saponins that trigger severe vomiting, diarrhea, and skin irritation in pets.
Symptoms to watch for: Repeated vomiting, diarrhea, abdominal pain, and red irritated skin around the mouth within 2-6 hours.
Safer swap: Swedish ivy trails beautifully from hanging planters and is classified as non-toxic to cats and dogs.
10. Tulip and Daffodil Bulbs (Tulipa and Narcissus spp.): Cardiac and Neurological Risk
Tulips and daffodils are spring favorites, but the highest concentration of toxins sits in the bulbs underground. Dogs are especially at risk because they may dig up and chew bulbs during planting season.
Tulip bulbs contain tulipalin A, while daffodil bulbs contain lycorine and calcium oxalate crystals. Ingestion causes severe vomiting, diarrhea, and abdominal pain. With large bulb consumption, pets can develop cardiac arrhythmias, convulsions, and respiratory depression that require emergency intervention. Tulip and daffodil bulbs contain concentrated cardiac and neurological toxins that can trigger arrhythmias and convulsions in pets.
Symptoms to watch for: Severe vomiting, diarrhea, drooling, rapid heartbeat, tremors, and difficulty breathing within 1-4 hours.
Safer swap: Orchids or roses provide elegant blooms without any bulb-based toxicity risk to pets.
11. Azalea and Rhododendron (Rhododendron spp.): Coma and Death Risk
Azaleas and rhododendrons contain grayanotoxins that interfere with sodium channels in cells throughout the body. Even a few leaves can poison a small cat or dog.
Symptoms begin with vomiting, diarrhea, and drooling, then progress to weakness, low blood pressure, and a dangerously slow heart rate. In severe cases, seizures and coma can develop within hours. Azaleas and rhododendrons contain grayanotoxins that disrupt cellular sodium channels, with just a few leaves capable of causing seizures or coma in small pets.
Symptoms to watch for: Vomiting, diarrhea, weakness, slow heartbeat, seizures, and collapse within 2-6 hours.
Safer swap: Camellia produces similar glossy evergreen foliage and showy flowers without grayanotoxin toxicity.
12. Sago Palm (Cycas revoluta): Liver Failure
The sago palm is a popular ornamental plant with a prehistoric appearance, yet it is one of the deadliest plants a pet owner can bring indoors. All parts contain cycasin and BMAA, with the seeds holding the highest concentration.
Cats and dogs that ingest sago palm material will vomit repeatedly, become lethargic, and may develop seizures as the toxins destroy liver cells. The mortality rate remains high even with aggressive veterinary treatment including activated charcoal, IV fluids, and liver support. Sago palm contains cycasin and BMAA toxins that cause acute liver failure in pets, with a high mortality rate even after emergency veterinary care.
Symptoms to watch for: Vomiting, diarrhea, lethargy, seizures, yellowing gums or eyes, and abdominal pain within 2-12 hours.
Safer swap: A parlor palm or areca palm offers a similar feathery tropical look and is completely non-toxic to pets.
13. Oleander (Nerium oleander): Potentially Fatal to All Pets
Oleander is an outdoor shrub in warm climates, but potted specimens are sometimes brought indoors. Every part of the plant — leaves, flowers, stems, and nectar — contains cardiac glycosides called oleandrin and nerine.
These compounds disrupt the electrical signaling of the heart. Pets that chew oleander leaves can develop irregular heart rhythms, dangerously low blood pressure, tremors, and seizures. Even the smoke from burning oleander wood is toxic. Oleander contains cardiac glycosides in every part of the plant that can cause fatal heart arrhythmias in cats, dogs, and other pets.
Symptoms to watch for: Vomiting, diarrhea, irregular heartbeat, weakness, tremors, and collapse within 1-4 hours.
Safer swap: Orchids provide long-lasting blooms and are classified as non-toxic to both cats and dogs.
14. Lilies (Lilium and Hemerocallis spp.): Fatal Kidney Failure in Cats
Lilies are the single most dangerous plant for cat owners. Every part of the plant — petals, leaves, stems, pollen, and even the water in a vase — contains an unidentified nephrotoxin that destroys renal tubules.
A cat need only ingest a tiny amount of pollen while grooming its fur, or drink water from a lily vase, to develop acute kidney failure within 24 to 72 hours. Early signs include vomiting and lethargy, but by the time symptoms appear, irreversible damage may have already occurred. No part of any true lily is safe for cats — even pollen on fur or water from a vase can cause fatal kidney failure within days.
Symptoms to watch for: Vomiting, lethargy, loss of appetite, increased thirst, and then decreased or absent urination within 6-24 hours.
Safer swap: Gerbera daisies, orchids, or roses provide showy blooms without any risk to cats or dogs.
Frequently Asked Questions
Are spider plants toxic to cats?
No. Spider plants are classified as non-toxic to cats and dogs by the ASPCA. If a cat eats large amounts of spider plant leaves, mild stomach upset or vomiting can occur simply from eating too much foliage, but the plant itself contains no toxic compounds.
Are peace lilies toxic to cats?
Yes. Peace lilies contain calcium oxalate crystals that cause oral burning, heavy drooling, and vomiting in cats. They are not true lilies and do not cause the fatal kidney failure associated with Lilium species, but they still require prompt veterinary attention if ingested.
Is lavender safe for cats?
Lavender contains linalool and linalyl acetate, compounds that are toxic to cats and dogs in concentrated forms. Small amounts of fresh lavender typically cause only mild stomach upset, but essential oils and large quantities of dried lavender pose a greater risk.
What should I do if my pet eats a toxic plant?
Remove any remaining plant material from your pet’s mouth, identify the plant if possible, and contact your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 immediately. Do not attempt to induce vomiting unless instructed by a veterinary professional.
Are succulents safe for dogs?
Not all succulents are safe. Jade plants and aloe vera are toxic to dogs, while echeveria, haworthia, and burro’s tail are considered non-toxic. Always verify the specific species before bringing a succulent into a home with pets.
The Bottom Line
Protecting your pets starts with knowing what is in your home. If you own any of the plants on this list, relocate them to pet-free rooms or replace them with verified non-toxic alternatives from our guides to cat-safe plants and dog-safe plants. When in doubt, check any plant before purchase — your pet’s safety depends on it.
