8 Poisonous Plants to Cats

Your garden may have some poisonous plants cats like to chew. If you have a cat, you should avoid certain varieties of ornamental plants. Cats are occasional chewers of garden foliage and are immune to most homegrown plants. However, some garden plants could prove very harmful to them. When ingested, these plants can cause mild-to-moderate and occasionally severe reactions. It is best to be acquainted with the most common plants that should be avoided among cat owners: 

1. Lilies

These are the most dangerous plants to have in your garden if you own a cat. Most varieties of lilies have proven to be toxic for cats. In most plants, only a certain part, like the seeds or the tubers are poisonous. However, in lilies the entire plant is equally toxic. Any part of the lily plant, including the flower, in the smallest of amounts can cause severe damage to your cat’s health. 

Common clinical signs include vomiting, lethargy, diarrhea and physical weakness. Serious medical condition like kidney failure and cardiac arrest is possible if the cat isn't immediately taken to a vet. 

The most common varieties of lilies that are found in ornamental gardens include: 


  • Family: Amaryllidaceae
  • Common Name: Saint Joseph lily, Cape Belladonna, Belladonna lily
  • Scientific Name: Amaryllis sp
  • Toxic Compound: mainly Lycorine

Clinical symptoms among cats with Amaryllis poisoning include abdominal pain and hypersalivation along with body tremors. 

Asian Lily

  • Family: Liliaceae
  • Common Names: Asiatic Lily
  • Scientific Name: Lilium asiatica

2. African Wonder Tree

This is a favored ornamental plant in the entire North America region. It is toxic for all common household pets, including cats. 

  • Scientific Name: Ricinus communis
  • Toxic Compound: Ricin

Ricin is a highly-potent chemical that is found in high concentration in this plant. The smallest amount of its foliage can cause severe reactions in cats. The symptoms begin to show after 24 hours from ingesting the plant. The primary symptoms are mostly physical and are often confused with flu-like symptoms. This is why this form of poisoning is so fatal — often the vets diagnose it as a case of mild flu. If the symptoms aren't controlled within three days from the first sign of symptoms, death is almost certain. 

Typical clinical symptoms include loss of appetite along with excessive thirst and physical weakness. Some poisoned cats may start trembling and showing signs of colic pain and extreme sweating. If the symptoms turn into labored breathing and bloody diarrhea, it means that the toxin has seeped much deeper and damage to the central nervous system is certain. 

3. Christmas Rose

  • Family: Ranunculaceae
  • Common Name: Lenten Rose, Hellebore or Easter Rose
  • Scientific Name: Helleborus niger
  • Toxic Compound: Veratrin

Clinical signs include excessive drooling along with repeated episodes of abdominal pain and diarrhea. Sometimes the physical symptoms are suppressed and instead the cat may seem very depressed and sluggish. 

4. Azalea

  • Family: Ericaceae
  • Common Name: Rhododendron and Rosebay
  • Scientific Name: Rhododendron spp
  • Toxic Compound: Grayantoxin 

This plant is the most common cause of poisoning among cats. Often the symptoms do not subside even with repeated dosage of medications. 

Within a few hours, a cat with Azalea leaves in its gut can start suffering from total lack of mental coordination along with stupor or even a paralysis-like condition. Other symptoms include vomiting, diarrhea and cardiovascular arrest. 

Other not-so-dangerous toxic plants that can cause moderate poisoning among casts are: 

5. Chrysanthemum

  • Family: Compositae
  • Common Name: Daisy or Mum
  • Scientific Name: Chrysanthemum spp
  • Toxic Compound: Lactones
  • Clinical Symptoms — vomiting, hyper salivation, diarrhea and skin rashes

6. Cycads

  • Family: Cycadaceae
  • Common Name: Sago Palm or Fern Palm
  • Scientific Name: Cycas or Zamia
  • Toxic Compound: neurotoxins
  • Clinical Symptoms — bloody vomiting and dark stools along with excessive thirst and skin bruising 

7. Daffodil

  • Family: Amaryllidaceae
  • Common Name: Jonquil, Narcissus and Paper White
  • Scientific Name: Narcissus spp
  • Toxic Compound: Lycorine
  • Clinical Symptoms — vomiting and diarrhea along with occasional convulsions and low blood pressure 

8. Elephant Ears 

  • Family: Araceae
  • Common Names: Caladium, Taro and Ape
  • Scientific Name: Caladium hortulanum
  • Toxic Compound: crystals of calcium oxalate
  • Clinical Symptoms — oral pain, burning around the mouth, swollen lips and tongue, drooling and vomiting