FrançaisWhich plants are toxic to dogs and cats?
Most plant exposures in dogs and cats cause mild to moderate vomiting and diarrhea. Damage to the liver, kidneys, heart or nervous system is rare, but a few garden and house plants can cause it after a small amount [2]. The ones most often behind serious cases include lilies, azalea, oleander, sago palm, kalanchoe and autumn crocus [2]. Plants that act on the heart, such as oleander and foxglove, are among the most toxic of all [1].
If your dog or cat has chewed one of them, do not wait for signs. Call your vet or a pet poison line now [4, 7]. For foods such as chocolate or grapes, see toxic foods for dogs and cats.
Toxic plants at a glance
Where a detailed article exists, the line links to it. Mushrooms and blue-green algae are not plants, but dogs meet them outdoors in the same places.
| Plant | Most at risk | What it harms | When signs appear | Main tests the vet uses |
|---|---|---|---|---|
| Lilies (true lilies and daylilies, including pollen and vase water) [1, 4] | Cats only; dogs get minor stomach upset [4] | Kidneys [1] | Drooling, vomiting within 1 to 3 hours; kidney failure within 24 to 72 hours [1, 4] | Creatinine, BUN, phosphorus and potassium every 24 hours for 3 days; urinalysis [1] |
| Sago palm and other cycads (the seeds are the most toxic part) [1, 8] | Dogs are extremely sensitive [1] | Liver, gut and nervous system [1] | Within 4 hours; liver failure within 48 to 72 hours [1] | Liver values daily for 3 days, bilirubin, blood glucose and clotting [1, 9] |
| Oleander, foxglove, lily of the valley and kalanchoe (cardiac glycosides) [1] | Dogs and cats; cats are thought to be more sensitive [1] | Heart: slow, fast or irregular beats; high potassium [1] | Within 2 hours; can last 4 to 5 days [1] | ECG and potassium; a digoxin blood test can react to these plants [1] |
| Autumn crocus (Colchicum) [1] | Dogs and cats [2] | Gut, then circulation (shock) [1] | Within hours; the course is long because the toxin leaves the body slowly [1] | Hydration and electrolytes [1] |
| Azalea and rhododendron (grayanotoxins) [1] | Dogs and cats [2] | Gut, nervous system and heart [1] | Within 1 to 4 hours, sometimes up to 12 hours; can last several days [1] | Heart rate, rhythm and blood pressure through the day [1] |
| Yew (the seed inside the red berry and the needles; the red flesh is not toxic) [1] | Dogs, cats and horses [6] | Heart: slow beat up to cardiac arrest [1] | Sudden death is possible; early signs are tremors, breathing difficulty and seizures in dogs [6] | Heart rate and rhythm [1] |
| Dieffenbachia, philodendron, pothos, peace lily and calla lily (insoluble calcium oxalate) [1] | Dogs and cats [4] | Mouth and throat: pain, drooling, pawing at the mouth; rarely, swelling that hinders breathing [1, 4] | Right away, as soon as the plant is chewed [1, 4] | Usually none: most pets recover fully, often without treatment, and the kidneys are not harmed [1] |
| Tulip and daffodil (the bulbs are the most toxic part) [1, 5] | Dogs and cats [5] | Gut: vomiting, diarrhea, drooling [1, 5] | A small amount often causes few or no signs [1] | Hydration and electrolytes after a large amount [1] |
| Onion, garlic, leek and chive plants: dogs and cats | Cats most, then dogs [12] | Red blood cells [12] | Red cells usually break down 3 to 5 days later [12] | Blood count and smear for Heinz bodies [12] |
| Avocado (leaves are the most toxic part) [13] | Birds, rabbits, horses and livestock; dogs are fairly resistant [13] | Heart muscle in sensitive species; the pit can block a dog’s gut [13] | Heart signs within 24 to 48 hours in sensitive species [13] | No specific test exists [13] |
| Tomato plant (leaves and stems; ripe fruit is not toxic) [14] | Dogs, cats and horses [14] | Gut, weakness, slow heart rate [14] | Not well defined | Depends on the signs shown |
| Not a plant: death cap and other wild mushrooms [15] | Dogs; they absorb the toxin more than some other species [15] | Liver, then kidneys [15] | No signs for 6 to 12 hours; liver failure at 36 to 72 hours [15] | ALT, AST, ALP, bilirubin, glucose and clotting; amanitin test in some laboratories [15] |
| Not a plant: blue-green algae in ponds and lakes [16] | Dogs and other animals that drink the water [16] | Liver (microcystins) or nerves (anatoxins) [16] | Minutes to days [16] | ALT, ALP, bilirubin, glucose, potassium and clotting; testing of the water [16] |
Many plants share the same common name but belong to different families with different toxicity. That is why the vet needs to identify the exact plant, ideally with its scientific name [1].
Cats and dogs are not at risk from the same plants
- Lilies are a cat problem: lilies are not toxic to most animals, but cats are highly sensitive [1]. Licking a few pollen grains off the fur or drinking the vase water can cause fatal kidney failure in less than 3 days [4].
- Heart plants: cats are believed to be more sensitive than dogs to plants with cardiac glycosides, such as oleander and foxglove [1].
- Plants in general: in a review of poisonings in five European countries, including France, cats appeared more susceptible to plant toxins than dogs [19]. Cats can also reach hanging plants by climbing [1].
- Sago palm is a dog problem: dogs are extremely sensitive to cycads, with severe stomach, liver and nerve signs [1]. In a series of 60 dogs, 95% had liver and gut problems [9].
- Dogs chew more: dogs make up most plant calls to poison centers, ahead of cats [17, 18].
What to do right away
- Call now, even if your pet seems fine: your vet, an emergency clinic or a pet poison line, such as ASPCA Animal Poison Control at (888) 426-4435, open 24 hours a day (a fee may apply) [7], or Pet Poison Helpline at 855-764-7661 [4].
- Bring the plant or a photo of it: this helps the vet tell a dangerous lily from a less harmful one [4]. Keep the pot label too, if you have it: the scientific name matters [1].
- For a cat and a lily, do not wait for signs: if treatment is delayed by 18 hours or more, the kidney damage is generally irreversible [4].
- After a pond or lake swim: the vet may want a sample of the water the dog drank, including the bloom itself [16].
- No home remedies: do not try to make your pet vomit or give any product unless the vet tells you to. The vet first checks that it is safe for your pet [1].
What the vet checks, and why
The tests depend on which organ the plant attacks. That is why naming the plant matters so much [1]. Values are often repeated, because liver or kidney damage can show up 1 to 2 days after the plant was eaten [2, 9].
- Kidney values and urine (lilies): the vet takes a baseline blood count, chemistry panel and urinalysis, then checks kidney values every 24 hours for the first 72 hours. Rising creatinine, BUN, phosphorus and potassium show kidney damage [1]. See creatinine and BUN in cats.
- Liver values and clotting (sago palm, mushrooms, algae): after sago palm, liver enzymes are checked daily for 72 hours, with blood glucose and clotting tests if the liver is failing [1]. In one series, values did not change for 24 to 48 hours although signs appeared within a day; high bilirubin, ALP and ALT were the most common findings [9]. Dogs that died had higher ALT and bilirubin, lower albumin and more often prolonged clotting times (PT and PTT) [10]. See high ALT in dogs.
- Platelets: in 130 dogs that ate sago palm, a platelet count below 200,000/µL went with a higher risk of death [11].
- ECG and potassium (heart plants): with oleander, foxglove or lily of the valley, the ECG and blood potassium must be watched [1]. Potassium can rise because these plants block a pump in the cell membrane [1]. A blood test for the heart drug digoxin can react to these plants and help the diagnosis [1]. See potassium in dogs and cats.
- Heart rate and blood pressure (azalea): even when only a few leaves were eaten, the heart is usually watched through the day [1].
- Liver, sugar and clotting after mushrooms: death cap mushrooms can drop blood glucose, raise AST, ALT, ALP and bilirubin, and disturb clotting. Some laboratories can detect the toxin in blood or urine [15].
- Often no blood test (mouth-irritating houseplants): most pets recover fully, often without treatment [1].
How often plant poisonings happen
Plant poisoning is less common in dogs and cats than in grazing livestock, and most cases involve common garden and house plants [3]. At the human poison center of Milan, plants made up 5.7% of animal calls from 2000 to 2011. Dogs were involved in 61.8% of these calls and cats in 26%. Most exposures (73.8%) caused mild to moderate signs. Where the outcome was known, 10.6% were fatal. Sago palm, poinsettia, hydrangea, oleander, rhododendron and cherry-family trees (Prunus) came up most often [17].
From 2015 to 2019, the same center received 932 calls about animal poisonings, 95 of them about plants. Dogs made up 67.8% of plant and venom calls and cats 26.3%; sago palm, poinsettia and hydrangea again led [18]. Pet Poison Helpline receives thousands of plant calls; its 10 most common are true lilies, cherry, azalea, tulip, peace lily, hydrangea, aloe, philodendron, daffodil and pothos [1].
In France, the national veterinary poison center in Lyon (CNITV) receives more than 22,000 calls a year about all poisons: 69.9% about dogs and 23.3% about cats [21].
Related articles
Other dangers in the home: essential oils and cats and permethrin and cats.
En français : plantes toxiques pour le chien et le chat.
Questions to ask your veterinarian
- Is the plant my pet chewed one of the dangerous ones, and what does it harm?
- Which tests does my pet need, and how often will they be repeated?
- Are the kidney values, liver values and potassium normal today?
- Does my pet need an ECG or clotting tests?
- How long should my pet stay under watch, and which signs should I look for at home?
Get your pet’s blood and urine results explained after a plant poisoning.
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Frequently asked questions
What is the most poisonous plant for dogs?
There is no single answer. The plants most often behind serious cases in dogs and cats include lily, azalea, oleander, sago palm, castor bean, kalanchoe and autumn crocus [2]. Oleander and foxglove are among the most toxic plants, and deaths occur even with treatment [1]. Dogs are extremely sensitive to sago palm: in two case series, 32.1% and 50% of dogs died [9, 10]. A French poison center reports that 2 or 3 oleander leaves can kill a 10 kg dog [20]. Call your vet or a pet poison line whatever the amount.
What are the most toxic house plants for dogs?
Sago palm, often grown indoors in smaller varieties, is one of the most dangerous for dogs: it can cause liver failure [1]. Kalanchoe contains heart toxins [1]. Popular houseplants such as peace lily, philodendron and pothos are among the plants poison lines hear about most, but they mainly irritate the mouth, and most dogs recover fully [1].
Do dogs know to avoid toxic plants?
Not reliably. Dogs make up most plant calls to poison centers, well ahead of cats [17, 18]. With some houseplants, such as dieffenbachia, the immediate mouth pain limits how much is eaten [1], but sago palm and oleander can harm after a small amount [1, 20]. Keep dangerous plants out of reach.
What happens if my cat sniffs a lily?
The danger is the pollen: it can stick to the face or fur, and licking a few grains while grooming can cause fatal kidney failure in less than 3 days [4]. If you see pollen on your cat or think it touched a lily, call your vet now. Treatment delayed by 18 hours or more generally leaves irreversible kidney damage [4].
What plants can I keep if I have a cat?
The ASPCA keeps a list of plants marked as toxic or non-toxic to cats, dogs and horses, and a guide to safer substitutes [5]. The FDA points to Pet Poison Helpline’s list of safer flowers for cats [4]. Do not bring true lilies or daylilies into the home, and do not plant them if your cat goes outside [4].
Sources
- Schmid RD. Houseplants and Ornamentals Toxic to Animals. Merck Veterinary Manual, updated 2024. merckvetmanual.com/toxicology/poisonous-plants/houseplants-and-ornamentals-toxic-to-animals
- Milewski LM, Khan SA. An overview of potentially life-threatening poisonous plants in dogs and cats. J Vet Emerg Crit Care. 2006;16(1):25-33. doi.org/10.1111/j.1476-4431.2005.00151.x
- Botha CJ, Penrith ML. Potential plant poisonings in dogs and cats in southern Africa. J S Afr Vet Assoc. 2009;80(2):63-74. doi.org/10.4102/jsava.v80i2.173
- US Food and Drug Administration. Lovely Lilies and Curious Cats: A Dangerous Combination. 2021. fda.gov/animal-veterinary/animal-health-literacy/lovely-lilies-and-curious-cats-dangerous-combination
- ASPCA Animal Poison Control Center. Toxic and Non-toxic Plants: Tulip. aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/tulip
- ASPCA Animal Poison Control Center. Toxic and Non-toxic Plants: Yew. aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/yew
- ASPCA Animal Poison Control Center. ASPCA Poison Control. aspca.org/pet-care/animal-poison-control
- Pet Poison Helpline. Sago Palm. petpoisonhelpline.com/poison/sago-palm
- Albretsen JC, Khan SA, Richardson JA. Cycad palm toxicosis in dogs: 60 cases (1987-1997). J Am Vet Med Assoc. 1998;213(1):99-101. pubmed.ncbi.nlm.nih.gov/9656033
- Ferguson D et al. Survival and prognostic indicators for cycad intoxication in dogs. J Vet Intern Med. 2011;25(4):831-837. doi.org/10.1111/j.1939-1676.2011.00755.x
- Lake BB et al. The characterization of cycad palm toxicosis and treatment effects in 130 dogs. Aust Vet J. 2020;98(11):555-562. doi.org/10.1111/avj.13007
- Hayes C. Garlic and Onion (Allium spp) Toxicosis in Animals. Merck Veterinary Manual, updated 2024. merckvetmanual.com/toxicology/food-hazards/garlic-and-onion-allium-spp-toxicosis-in-animals
- Hayes C. Avocado (Persea spp) Toxicosis in Animals. Merck Veterinary Manual, updated 2024. merckvetmanual.com/toxicology/food-hazards/avocado-persea-spp-toxicosis-in-animals
- ASPCA Animal Poison Control Center. Toxic and Non-toxic Plants: Tomato Plant. aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/tomato-plant
- Puschner B. Toxin Latent Period >6 Hours After Ingestion of Mushrooms. Merck Veterinary Manual, updated 2024. merckvetmanual.com/toxicology/poisonous-mushrooms/toxin-latent-period-6-hours-after-ingestion-of-mushrooms
- Bischoff K. Algal Poisoning of Animals. Merck Veterinary Manual, updated 2024. merckvetmanual.com/toxicology/algal-poisoning/algal-poisoning-of-animals
- Caloni F et al. Plant poisoning in domestic animals: epidemiological data from an Italian survey (2000-2011). Vet Rec. 2013;172(22):580. doi.org/10.1136/vr.101225
- Bertero A et al. Plants and zootoxins: Toxico-epidemiological investigation in domestic animals. Toxicon. 2021;196:25-31. doi.org/10.1016/j.toxicon.2021.03.019
- Berny P et al. Animal poisoning in Europe. Part 2: Companion animals. Vet J. 2010;183(3):255-259. doi.org/10.1016/j.tvjl.2009.03.034
- Centre antipoison animal et environnemental de l’Ouest (CAPAE-Ouest), Oniris. Le laurier rose (in French). centre-antipoison-animal.com/laurier-rose.html
- Centre National d’Informations Toxicologiques Vétérinaires (CNITV), VetAgro Sup (in French). vetagro-sup.fr/recherche-expertise/centre-national-dinformations-toxicologiques-veterinaires-cnitv
Laboratory methods and reference intervals vary. This article explains; it does not diagnose. For a decision about your pet, use the original report and talk to your veterinarian. Our editorial policy.