There are many plants that are toxic to cats, and you might even already have some in your backyard. If you’re a cat owner (or about to become one), it is very important to always to check any plants that your cat could encounter in and around your home are safe.
Below are ten common plants that are moderately to highly toxic to cats you should avoid. However, it’s important to note that this list is not exhaustive. Check Greencross Vets’ A to Z list of toxic plants to make sure your home is free of toxic plants.
1. Lilies
Lilies are probably the most well-known toxic plants that affect cats. All parts of the plant, including the stem, leaves, flowers, pollen, and even the water from a vase in which lilies have been placed, can be potentially fatal if ingested. Even licking a small amount of pollen from their fur can be enough to cause toxicity.
There are many species of lilies. Some lilies only cause mild toxicity, such as oral irritation and signs of a gastrointestinal upset. The most dangerous lilies are those of the Hemerocallis and Lilium species (true lilies), such as Easter, Japanese show, Asiatic, stargazer, wood, red, western, tiger, and rubrum lilies. Daylilies are also extremely dangerous to cats.
Lily ingestion ultimately leads to kidney failure within 1-3 days of exposure. Cats that receive early veterinary treatment have a higher chance of recovery, but this condition can be irreversible so avoiding exposure in the first place is critical.
Signs of lily toxicity
Signs of toxicity occur quickly, typically within 2-4hrs of ingestion. Symptoms can include:
- Vomiting
- Diarrhoea
- Drooling
- Abdominal pain
- Inappetence
- Lethargy
- Increased thirst
2. Sago Palm/ Cycads
Sago palms and other types of cycads are highly toxic to dogs and cats. They’re commonly found in gardens and look like a small, bush-sized palm tree. The seed is the most toxic part, but all parts of the plant are toxic. Ingestion of even small quantities can result in severe poisoning and death.
Cycads contain a toxin called cycasin that is broken down in the gut into the toxic component methylazoxymethanol, which is responsible for most of the effects seen.
Signs of cycad toxicity
Toxicity results in severe liver damage and failure. Signs of toxicity include:
- Abdominal pain
- Vomiting
- Diarrhoea
- Weakness
- Lethargy
- Seizures
- Coma
- Death
3. Autumn crocus
Autumn crocus is a popular house and yard plant. All parts of the plant are considered toxic.
It contains colchicine and other alkaloids, and can cause significant illness, including multi-organ damage and bone marrow suppression in cats.
Signs of autumn crocus toxicity
If your cat is experiencing autumn crocus toxicity, you may notice:
- Bloody vomiting
- Diarrhoea
- Signs of shock, such as abnormal breathing patterns, abnormal heart rates, pale gums, and lethargy.
4. Oleander
Oleander is an outdoor shrub with delicate white and pink flowers. It is highly toxic to dogs and cats. All parts of the plant are toxic – as with lilies, even the water in the plant base can contain toxic components.
This plant contains naturally occurring toxins, called cardiac glycosides, that affect the heart.
Signs of Oleander toxicity
Toxicity can result in:
- Cardiovascular signs – abnormal heart rate and arrhythmias, weakness, respiratory changes
- Gastrointestinal signs – vomiting, drooling
- Neurological signs – tremors, seizures
5. Cyclamen
The beautiful cyclamen is a common household plant. All parts of the plant are toxic, especially the roots and tubers.
They contain irritating saponins — when any part of the plant is chewed, they can cause oral and gastrointestinal inflammation/irritation. With large ingestions these plants can cause heart issues, seizures, and death.
Signs of cyclamen toxicity
Signs your cat may have consumed cyclamen include:
- Drooling
- Vomiting
- Diarrhoea
- Abnormal heart rates
- Seizures
6. Chrysanthemums
These flowers vibrant flowers come in a large variety of types and colours and are highly toxic to cats.
They contain pyrethrins (which are also found in some dog flea and tick products), sesquiterpene, and lactone toxins. Cats are more sensitive to pyrethrins than dogs.
Signs of chrysanthemum toxicity
Signs of chrysanthemum ingestion include:
- Vomiting
- Diarrhoea
- Inappetence
7. Azaleas
Azaleas are a species of rhododendron. These small shrubs are less toxic than some of the larger rhododendron species, but still poisonous to cats if ingested. All parts of the plant are toxic. The consumption of small amounts is enough to cause toxicity.
These plants contain grayanotoxins which affect the muscles.
Signs of azalea toxicity
Signs of azalea toxicity include:
- Gastrointestinal signs – drooling, vomiting, diarrhoea, inappetence and abdominal pain)
- Cardiovascular signs – abnormal heart rate, arrhythmias, weakness, low blood pressure)
- Neurological signs – depression, tremors, transient blindness and seizures)
8. Daffodils, Hyacinths and Tulips
Daffodils, hyacinths and tulips are poisonous to both dogs and cats. The toxic components are most concentrated in the bulbs but can be found in all parts of the plant.
Daffodils contain multiple toxic components including oxalate crystals, alkaloids (especially lycorine) and glycosides. Both hyacinths and tulips belong to the Liliaceae family and contain allergenic lactones or similar alkaloids.
Signs of daffodil, hyacinth, and tulip toxicities
Ingestion of a small amount of the plant may only cause minor symptoms, including:
- Irritation to the skin, mouth and throat
- Digestive symptoms such as drooling, vomiting, diarrhoea
If larger amounts are ingested (especially the bulb) this can cause:
- Convulsions
- Tremors
- Changes to respiration and difficulty breathing
- Elevated heart rate and heart arrhythmias
9. Lantana
Considered a weed in Australia, this colourful, flowering shrub is part of the Verbenaceae family and is extremely toxic to cats and dogs.
The toxic compounds are lantana is pentacyclic triterpenoids. Toxicity can lead to liver failure, but that is more common in livestock than dogs and cats.
Signs of lantana toxicity
Signs of lantana toxicity include:
- Vomiting
- Diarrhoea
- Inappetence
- Weakness
- Laboured breathing
10. Philodendrons
There are many species of philodendron. Though usually less dangerous than many plants listed here, they still can cause significant irritation if chewed on, and can have some serious side effects if ingested.
These plants contain oxalate crystals. Chewing or biting this plant releases these crystals causing oral and gastrointestinal irritation and inflammation.
Signs of philodendron consumption
Your cat may show the following signs after biting or ingesting a philodendron:
- Drooling
- Pawing at the mouth
- Oral pain
- Decreased appetite
- Vomiting
- Swelling of the upper airways (in rare cases)
Keep your cat safe by removing these toxic plants from your household. If you’re ever concerned your cat may have consumed part of a toxic plant, call your veterinarian or closest veterinary emergency hospital for advice.