Plants toxic to cats
One group matters more than all the others: true lilies (Lilium) and daylilies (Hemerocallis). The FDA states that the entire lily plant is toxic — the stem, leaves, flowers, pollen, and even the water in a vase — and that in cats this leads to kidney damage and then kidney failure. Everything else on this page sits below that, from the cardiac-glycoside plants like oleander to the common houseplants whose calcium oxalates cause painful but usually self-limiting mouth irritation.
Updated on 2026-10-07.
If your animal has eaten part of a plant, do not wait for symptoms and do not try to treat it at home: consult a veterinarian straight away, or call the ASPCA Animal Poison Control Center on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661.
True lilies (Lilium): the FDA describes the entire plant, pollen and vase water included, as toxic to cats.
The facts in one table
| Plant | Scientific name | Toxic principle | What it does |
|---|---|---|---|
| Lily of the valley | Convallaria majalis | cardenolídeos (convalarina e outros) | potentially fatal |
| Sago palm / cycad | Cycas revoluta | cicasina | potentially fatal |
| Daylily | Hemerocallis spp. | nefrotoxina ainda não identificada | potentially fatal |
| True lilies (Asiatic, Easter, Oriental, tiger, stargazer) | Lilium spp. | nefrotoxina ainda não identificada | potentially fatal |
| Oleander | Nerium oleander | glicosídeos cardíacos | potentially fatal |
| Azalea and rhododendron | Rhododendron spp. | graianotoxina | serious |
| Aloe vera | Aloe vera | saponinas e antraquinonas | digestive upset |
| Tulip | Tulipa spp. | tulipalina A e B | digestive upset |
| Dieffenbachia / dumb cane | Dieffenbachia spp. | oxalatos de cálcio insolúveis e enzima proteolítica | mouth irritation |
| Golden pothos / devil's ivy | Epipremnum aureum | oxalatos de cálcio insolúveis | mouth irritation |
| Monstera / Swiss cheese plant | Monstera deliciosa | oxalatos de cálcio insolúveis | mouth irritation |
Toxic principles and species affected as published by the ASPCA Animal Poison Control Center, the Pet Poison Helpline and the FDA. The ASPCA states its own list is not meant to be all-inclusive.
Sources: ASPCA Animal Poison Control Center · U.S. Food and Drug Administration · Pet Poison Helpline · ASPCA
Lilies are the emergency
The FDA names the dangerous group precisely: Lilium species, which covers Asiatic, Easter, Oriental, rubrum, stargazer, tiger and wood lilies, and Hemerocallis, the daylilies. It describes the whole plant as toxic including the pollen and the vase water, which is why a cat that has brushed against a bouquet and groomed itself is a case and not a false alarm. The timeline the FDA gives runs from decreased activity, drooling, vomiting and loss of appetite in the first twelve hours, through the onset of kidney damage between twelve and twenty-four hours, to kidney failure between twenty-four and seventy-two hours.
The practical conclusion is unusually simple for a toxicity page: do not have true lilies or daylilies in a house with a cat, and do not accept them in a bouquet. A plant whose pollen alone can start that sequence is not manageable by putting it on a high shelf.
If your animal has eaten part of a plant, do not wait for symptoms and do not try to treat it at home: consult a veterinarian straight away, or call the ASPCA Animal Poison Control Center on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661.
Sources: U.S. Food and Drug Administration · Pet Poison Helpline
Not everything called a lily is a lily
The naming is genuinely confusing and the stakes make it worth untangling. The FDA separates out the plants with "lily" in the name that are far less harmful: calla lilies and peace lilies cause localised irritation only, and the Peruvian lily causes mild stomach upset. It also flags two more that are dangerous for different reasons — lily of the valley and the gloriosa or flame lily, which are not Lilium at all.
So "is this lily dangerous?" depends on the botany, not the common name. Lily of the valley is Convallaria majalis, and the ASPCA gives its toxic principles as cardenolides, including convallarin, with effects that include irregular heartbeat and low blood pressure — a different mechanism from the kidney injury caused by true lilies, and dangerous to dogs as well as cats.
Sources: U.S. Food and Drug Administration · ASPCA Animal Poison Control Center
The common houseplants: painful, rarely fatal
Monstera, pothos and dieffenbachia all share one toxic principle — insoluble calcium oxalates — and one clinical picture: oral irritation, intense burning of the mouth, tongue and lips, drooling, vomiting and difficulty swallowing. Dieffenbachia adds a proteolytic enzyme to the mix. These are the plants behind most "my cat chewed a leaf" calls, and the usual outcome is a very unhappy animal rather than a critical one.
That is not a reason to shrug. The oxalate crystals cause real pain, swelling in the mouth can interfere with swallowing, and the dose a particular cat took is not something you can judge by looking at the leaf. It is still a call, just not the same category of call as a lily.
Sources: ASPCA Animal Poison Control Center · ASPCA Animal Poison Control Center · ASPCA Animal Poison Control Center
What to do, and what not to do
The FDA's instruction is to call immediately: if you suspect your cat has eaten any part of a lily, or its pollen, or has drunk water from a vase containing lilies, contact your veterinarian or a pet poison control centre. Bring the plant or a photograph of it, because identification changes what happens next. The two things not to do are waiting to see whether symptoms appear and attempting anything at home.
- ASPCA Animal Poison Control Center: (888) 426-4435
- Pet Poison Helpline: (855) 764-7661
If your animal has eaten part of a plant, do not wait for symptoms and do not try to treat it at home: consult a veterinarian straight away, or call the ASPCA Animal Poison Control Center on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661.
Sources: U.S. Food and Drug Administration · ASPCA Animal Poison Control Center · Pet Poison Helpline
Monstera deliciosa: insoluble calcium oxalates, causing painful mouth irritation.
What most people get wrong
- "Only the bulb or the leaves are dangerous." For true lilies the FDA says the entire plant is toxic, including the pollen and the water in the vase.
- "A peace lily is a lily." It is not. The FDA groups calla lilies and peace lilies among the plants causing localised irritation only.
- "Wait and see if the cat gets ill." With lilies, kidney damage begins in the first twelve to twenty-four hours. The FDA says to call immediately.
- "The ASPCA list is complete." The ASPCA itself states the list is not meant to be all-inclusive but a compilation of the most frequently encountered plants.
Sources: U.S. Food and Drug Administration · ASPCA Animal Poison Control Center
Frequently asked questions
- Which plants are most dangerous to cats?
- True lilies (Lilium) and daylilies (Hemerocallis). The FDA describes the entire plant as toxic, including pollen and vase water, leading to kidney damage and kidney failure.
- Is monstera poisonous to cats?
- The ASPCA lists it as toxic to cats and dogs, with insoluble calcium oxalates causing oral irritation, intense burning of the mouth, drooling, vomiting and difficulty swallowing.
- What should I do if my cat ate a lily?
- Call your veterinarian or a pet poison control centre immediately — the ASPCA Animal Poison Control Center on (888) 426-4435 or the Pet Poison Helpline on (855) 764-7661 — and do not wait for symptoms.
- Is a plant safe if it is not on the ASPCA list?
- Not necessarily. The ASPCA states that its list is not all-inclusive; it covers the most frequently encountered plants.
How to read the numbers
The numbers on “Plants toxic to cats” come from the facts table at the top, with the official source alongside.
Where the data comes from
Each section of “Plants toxic to cats” names its source (agency, university or breed club) with a verification date.
What this page doesn’t replace
Educational information, not a substitute for a vet, agronomist or specialist assessing your specific case.
Go deeper at the official source
To go deeper than “Plants toxic to cats”, the source named below publishes the original document.
Words on this page
Toxicity
A plant’s or substance’s capacity to harm an organism, which varies with the species exposed, the amount ingested and the animal’s size. A plant "toxic to dogs" is not necessarily toxic to humans at the same dose, and the reverse holds too.
Standard definition by ASPCA — Animal Poison Control Center · Toxicity
Hypoallergenic
A term used for breeds that shed less allergen into the environment, usually because they shed less fur. No dog or cat breed is fully allergen-free: a cat’s main allergen comes from saliva and skin, not only fur, and a very sensitive person can react to any breed.
Standard definition by American Kennel Club · Hypoallergenic
Life cycle
The sequence of stages an organism passes through from birth to death — for an animal, young, adult and senior; for a plant, germination, growth, flowering and, in annuals, death after setting seed.
Dormancy
The period when a plant slows its metabolism and stops visible growth, usually in autumn and winter, to survive cold or drought. Pruning, transplanting or fertilising during dormancy is usually less stressful for the plant than doing it in full growth.
Hemisphere
Half of the globe split by the equator. The seasons flip between the two: when it is winter in the northern hemisphere, it is summer in the southern one, which shifts the pruning, bloom and harvest calendar described on this page.
Formative pruning vs. maintenance pruning
Formative pruning happens in a plant’s first years and sets the permanent shape of the main branches; maintenance pruning is yearly, removes dead, diseased or crossing branches, and does not change the plant’s architecture. Mixing the two up is the most common reason a fruit tree fails to bear fruit.
Sources
- Toxic and Non-Toxic Plants List — ASPCA Animal Poison Control Center. Checked on 2026-10-07. A própria ASPCA avisa que a lista "não pretende ser completa", e sim reunir as plantas mais encontradas.
- Lovely Lilies and Curious Cats: A Dangerous Combination — U.S. Food and Drug Administration. Checked on 2026-10-07.
- Lilies are toxic to cats — Pet Poison Helpline. Checked on 2026-10-07.
- Top 10 Toxic Plants for Pets: What to Look Out For — ASPCA. Checked on 2026-10-07.
- Toxic and Non-toxic Plants: Lily of the Valley — ASPCA Animal Poison Control Center. Checked on 2026-10-07.
- Toxic and Non-toxic Plants: Cutleaf Philodendron (Monstera deliciosa) — ASPCA Animal Poison Control Center. Checked on 2026-10-07.
- Toxic and Non-toxic Plants: Golden Pothos — ASPCA Animal Poison Control Center. Checked on 2026-10-07.
- Toxic and Non-toxic Plants: Dieffenbachia — ASPCA Animal Poison Control Center. Checked on 2026-10-07.