Toxic Plants: How Houseplants Can Harm Pets
Posted by Jason Wyrwicz on May 5th 2025
Dogs and cats are many things to many people —a best friend, a companion, a family member. And, in the cases of many plants that are growing within the walls of our homes, and even outside in our gardens, our pets could be in danger.
Your favorite household plants could be harming your cat or dog, evidenced by calls to the American Society for the Prevention of Cruelty to Animals (ASPCA) Poison Control hotline . It receives approximately 150,000 calls annually from pet owners seeking help with accidental poisonings. About a quarter of all pets poisoned by non-drug products are poisoned by plants.
Based on a list of toxic plants from UC Davis School of Veterinary Medicine’s most common causes of emergency calls and Texas A&M ’s “Common Poisonous Plants and Plant Parts, ” we’ve compiled a toxic plants guide, breaking down the risks to your cat and/or dog and warning signs to look out for.
Why Are Some Plants Dangerous to Pets?
Cats and dogs may chew plants out of boredom, curiosity, or an upset stomach. But many popular garden and indoor plants contain compounds that are harmful—or even fatal—to animals. From vomiting and drooling to seizures and organ failure, toxic plants can cause a range of dangerous symptoms.
Toxic Plants That Could Harm Your Pets
1. Castor Bean (Ricinus communis)
Castor bean tops the toxicity charts for household plants. The attractive, spiky seed pods hide glossy seeds packed with ricin—a poison potent enough that chewing just one can send a dog or cat into sudden vomiting, bloody diarrhea, seizures and lethal dehydration.
- Toxic to: Dogs & Cats
- Toxic parts: Seeds and leaves
- Symptoms: Vomiting, bloody diarrhoea, dehydration, tremors, seizures
- Fact: Castor bean tops the list as the No.1 most reported toxic plant for pets and contains the deadly toxin ricin.
2. Caladium (Elephant Ear, Angel Wings)
Those show‑stopping leaves come at a price: they’re laced with sharp calcium‑oxalate crystals. Pets that nibble the foliage experience an instant burn in the mouth and throat, leading to drooling, retching and frantic pawing at the face.
- Toxic to: Dogs & Cats
- Toxic parts: Leaves
- Symptoms: Drooling, vomiting, oral irritation, difficulty swallowing
- Fact: Accounts for 13% of all toxic plant exposures. Ranked 4th most common plant poisoning in pets.
3. Lilies (Lilium species)
To cats, every part of a true lily is disastrous. A single lick of pollen or sip of vase water can shut down the kidneys within 48 hours. Early signs—vomiting and listlessness—feel mild but quickly spiral to irreversible renal failure.
- Toxic to: Cats (extremely)
- Toxic parts: All parts including petals, pollen, and water from the vase
- Symptoms: Vomiting, lethargy, loss of appetite, kidney failure
- Fact: Even a small exposure—like licking pollen—can be fatal to cats.
4. Dumbcane (Dieffenbachia)
Common in offices, dumbcane releases microscopic needles when bitten. Within minutes your pet may drool, gag and struggle to swallow as the oral tissues swell painfully.
- Toxic to: Dogs & Cats
- Toxic parts: Leaves and stems
- Symptoms: Oral pain, drooling, vomiting, swelling of mouth/throat
- Fact: Causes immediate burning and irritation due to oxalate crystals.
5. Rosary Pea (Abrus precatorius)
The vivid red‑and‑black seeds look like beads but contain abrin, a toxin even deadlier than ricin. If chewed, they can provoke severe abdominal pain, tremors and multi‑organ collapse.
- Toxic to: Dogs & Cats
- Toxic parts: Seeds
- Symptoms: Tremors, seizures, vomiting, difficulty breathing, organ failure
- Fact: Contains abrin, a highly potent toxin—chewing just one seed can be deadly.
6. Larkspur
Young larkspur plants are especially noxious. Ingesting them interferes with neuromuscular function, producing stiffness, muscle tremors, drooling and in extreme cases fatal respiratory or heart failure.
- Toxic to: Dogs & Cats
- Toxic parts: Entire plant
- Symptoms: Tremors, stiffness, drooling, paralysis, heart failure
- Fact: Toxic even in small doses, especially to young animals.
7. Foxglove (Digitalis purpurea)
Famous for its bell‑shaped blooms, foxglove manufactures cardiac glycosides. Dogs or cats that sample the leaves can suffer nausea, erratic heartbeats, weakness and sudden collapse.
- Toxic to: Dogs & Cats
- Toxic parts: Entire plant
- Symptoms: Vomiting, irregular heartbeat, weakness, collapse
- Fact: Contains cardiac glycosides—can disrupt heart function rapidly.
8. Autumn Crocus (Colchicum autumnale)
This fall‑flowering bulb hides colchicine, a compound that quietly destroys dividing cells. Symptoms—vomiting, bloody diarrhoea, abdominal pain—may be delayed for days, masking progressing liver and kidney damage.
- Toxic to: Dogs & Cats
- Toxic parts: Bulbs, flowers
- Symptoms: Vomiting, diarrhoea (possibly bloody), organ damage, seizures
- Fact: Toxic effects can appear days after ingestion and may be fatal.
9. Black Locust (Robinia pseudoacacia)
Chewing the bark, leaves or seedpods of a black locust tree leaves pets weak, depressed and shaky. Large doses dilate the pupils, slow breathing and can prove fatal without intervention.
- Toxic to: Dogs & Cats
- Toxic parts: Bark, leaves, seeds
- Symptoms: Weakness, depression, dilated pupils, vomiting
- Fact: All parts are toxic, especially when chewed.
10. Yew (Taxus species)
Every needle and berry of a yew tree contains taxines that halt the heart. Animals often show only trembling and shortness of breath before suffering sudden cardiac arrest.
- Toxic to: Dogs & Cats
- Toxic parts: Needles, seeds, bark
- Symptoms: Drooling, muscle tremors, seizures, heart failure
- Fact: A small amount can cause sudden death due to heart toxicity.
11. Oleander
Oleander’s milky sap teems with the same cardiac toxins used in some heart medications—except at overdose strength. A tiny mouthful is enough to cause vomiting, severe bradycardia and death in both dogs and cats.
- Toxic to: Dogs & Cats
- Toxic parts: Entire plant
- Symptoms: Vomiting, slowed heart rate, diarrhoea, death
- Fact: Just a few leaves can be lethal due to potent cardiac toxins.
If Your Pet Eats a Toxic Plant
Stay calm but move fast.
Phone your vet or a 24‑hour poison‑control hotline as soon as you suspect ingestion—minutes matter with plant toxins.
Unless a professional instructs you, do not induce vomiting or give home remedies; certain poisons burn twice on the way back up.
Bring a fresh sample or clear photo of the plant, plus a note of when and how much your pet might have eaten, so the clinic can tailor treatment immediately.
Keep your animal warm, quiet and under close watch en route to care; symptoms can escalate without warning.
Tips to Keep Pets Safe from Toxic Plants
A few easy habits can all but eliminate the risk of a poison emergency.
First, learn the names of every plant you own or label them clearly, so you can give your vet instant information if trouble strikes.
Position any risky greenery on high shelves, in hanging baskets or behind closed doors, and fence off toxic shrubs in the garden.
Supervise curious chewers outdoors and redirect them toward toys or pet‑safe grasses.
Finally, post your veterinarian’s number and a 24‑hour poison‑control hotline somewhere visible—quick action saves lives
Final Thoughts
Plants make our living spaces brighter, but even a single bite of the wrong leaf can trigger a life‑threatening reaction. Identify every plant you bring indoors or grow outside, swap risky species for pet‑safe alternatives, and place any questionable greenery well out of paws’ reach. If you suspect your dog or cat has sampled something toxic, phone your vet or a poison‑control hotline straight away—acting within minutes can save their life.
Sources
- https://foresttrailsanimalhospital.com/news/why-does-my-pet-eat-strange-and-inappropriate-things
- https://www.petpoisonhelpline.com/poison/castor-bean-2/
- https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/castor-bean-plant
- https://pubmed.ncbi.nlm.nih.gov/10825094/
- https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/caladium
- https://mountsinai.org/health-library/poison/caladium-plant-poisoning
- https://www.fda.gov/animal-veterinary/animal-health-literacy/lovely-lilies-and-curious-cats-dangerous-combination
- https://www.aspca.org/news/which-lilies-are-toxic-pets
- https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/dieffenbachia
- https://lortsmith.com/need-help-now/cat/poisons-toxins/toxic-plants/dieffenbachia/
- https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/rosary-pea
- https://wagwalking.com/condition/larkspur-poisoning
- https://www.petpoisonhelpline.com/poison/larkspur/
- https://vetmeds.org/pet-poison-control-list/foxglove/
- https://veteris.co.uk/petcare-advice/are-foxgloves-poisonous-to-dogs
- https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/autumn-crocus
- https://www.petpoisonhelpline.com/poison/black-locust/
- https://vetmeds.org/pet-poison-control-list/yew/
- https://www.dvm360.com/view/dangerous-beauty-oleander-toxicosis-dogs-horses-and-more
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10220692/
