Shock and Gnaw: Common Plants That Are Toxic To Cats and Dogs

Many common houseplants are toxic to dogs and cats. And calling something “toxic” might mean any number of things because figuring out plant toxicity is more complex than first meets the eye. For example:

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  Babys breath and company

  Some plants are just irritants, some are dangerous, some are extremely dangerous, and eating a few of these would constitute a dire emergency.

• Some plants have both poisonous and safe – or even beneficial – parts. For example, the bark, stems, and leaves of avocado trees are toxic to animals, but avocado fruit is perfectly safe. Actually, avocado fruit is used in many dog and cat food and supplements because it‘s high in essential fatty acids, vitamin A, vitamin C,  vitamin E, potassium, and many other nutrients. In addition, avocado fruit contains no cholesterol, has very little sodium, and is high in monosaturated fats.
• Some plants are toxic if they’re eaten raw, but are safe if they’re cooked or in powdered form (or vice versa).
• The intensity of the reaction depends on a number of factors: the part of the plant ingested, the amount ingested, an individual’s existing health conditions, and the animal’s overall toxic load.
• Plants that are considered nontoxic can still cause severe symptoms in a specific dog or cat with an allergy to that plant.
• Ingesting nontoxic plants can also lead to symptoms of toxic exposure if they have been sprayed with poisonous chemicals.

Which plants are toxic?

The list below is of common plants that are considered to be the most toxic to cats and dogs. I can’t list every single plant that might be toxic because of the enormous number of plants our cats and dogs encounter.

In this chart:

(*) Means plants have both toxic parts and safe parts.
(c) Means plants are toxic to cats but not dogs.
(d) Means plants are toxic to dogs but not cats.
(1) Means there is controversy about the level of toxicity.
(2) Means there are some toxic varieties and some safe varieties.

Symptoms of toxic exposure

Fern (photo by Erusalio)

If a dog or cat ever shows symptoms of toxicosis, contact a veterinary professional (Olympia’s 24-hr Pet Emergency hospital #455-5155) or call an animal poison control center as soon as possible.

The signs of exposure can appear immediately or can show up as much as 15 hours after sampling toxic plants, so people should act quickly if they see an animal exhibiting symptoms of exposure. If you know what they ate, get a sample of it – this helps veterinarians more quickly identify the toxin and decide on a treatment strategy.

Severe or persistent vomiting is the most common sign of a problem, so a veterinarian should be contacted if you see this happening. That said, dogs and cats often vomit after chewing on plants so this symptom alone does not always represent “toxic poisoning”. Animals usually are not facing a life and death situation when they experience sporadic vomiting without other signs of illnesses (such as seizures, loss of consciousness, difficulty breathing, diarrhea, or loss of appetite). But talking with a vet is the best thing to do if you’re concerned or if you suspect they ate something toxic. NOTE: inducing vomiting is sometimes the worst possible tactic, so don’t take this step without first getting a veterinarian’s advice.

Other common symptoms of eating something toxic include excessive drooling, shivering, muscle spasms, panting, swelling, convulsions, bleeding from orifices, and coma.

Select sources

• American Society for the Prevention of Cruelty to Animals (ASPCA). “Toxic and Non-Toxic Plants.” 30 July 2011. http://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants . (Includes photos of toxic plants.)
• American Veterinary Medical Association (AVMA). “Guide to Small Animal Poisons.” 30 July 2011. http://www.petalk.com/poisons.html (Lists toxic plants and other household poisons.)
• Department of Plant Sciences at the University of California Davis. “Poisonous Plant Brochure.” 30 July 2011. http://ucanr.edu/sites/poisonous_safe_plants/files/154528.pdf (Lists plants that are toxic to humans & can be sorted either by common name or scientific name.)