Five Plants Every Cat Owner Should Treat with Caution

In this guide

A bunch of lilies and roses can look wonderful on a kitchen table, and it is easy to assume there is no harm in a kitten batting playfully at the petals. But when a cat goes on to chew on fallen petals, what looks like harmless curiosity can turn into a genuine emergency, with a vet's response being nothing short of urgent.

Which plants pose a risk to cats?

The scale of the problem may come as a surprise: the ASPCA lists 417 varieties of plant that are toxic to cats, against 569 that are considered safe. It seems remarkable that cats manage to live long, healthy lives surrounded by so many potentially dangerous plants, but the answer lies partly in how broadly "toxic" is defined. Some toxic plants cause nothing worse than a mild skin rash or short-lived vomiting, while others can severely damage internal organs and lead to life-threatening problems such as kidney failure.

Why do cats eat plants in the first place?

It seems an odd habit for an obligate carnivore. According to holistic veterinarian Dr Patrick Mahaney, a nutritional shortfall in a cat's diet may sometimes drive it to nibble on plant material. Cats may also be seeking extra moisture, particularly if they mainly eat dry food, or may chew on plants deliberately to induce vomiting when they feel nauseated.

Most problems arise when a cat actually chews or eats a plant, though skin contact can also cause irritation in some cases. The pencil cactus, for example, contains a milky sap that can cause dermatitis on areas of skin with less protective fur, while poison ivy and poison oak can trigger itchy, blistering skin reactions in cats, just as they can in people, if the toxic oils penetrate the fur.

1. Lilies

Lilies have such a poor reputation among cat owners that Pet Poison Helpline runs a dedicated awareness campaign called No Lilies for Kitties. Dr Mahaney notes that lily-induced toxicity is by far the most common plant exposure he sees in practice.

Lily poisoning triggers acute kidney failure in cats. Every part of the plant is toxic, leaves, roots, petals and pollen, and even the water from a vase of lilies can cause harm. This applies specifically to lilies in the Lilium and Hemerocallis genera, including familiar varieties such as the Tiger lily, Easter lily, Daylily and Stargazer lily. Other types, such as the Calla lily, Peace lily and Peruvian lily, are much less dangerous, causing irritation to the mouth and stomach but no lasting damage. Exactly how lilies damage the kidneys remains a mystery to researchers, but the effect, rapid and potentially irreversible kidney failure, is well documented.

2. Sago palms

Resembling miniature palm trees, sago palms go by a number of names, including coontie palm, cardboard palm, cycad and zamia, and belong to the genera Cycas, Zamia and Macrozamia. They are popular houseplants and are also grown outdoors in warmer regions.

Every part of the sago palm contains a toxin called cycasin, and exposure can cause gastrointestinal upset followed by nervous system symptoms and serious liver damage. Pet Poison Helpline warns that a cat or dog that eats sago palm needs emergency veterinary care immediately, and even with prompt treatment, only around half of affected animals survive.

3. Azaleas and rhododendrons

Closely related and both belonging to the genus Rhododendron, these shrubs are toxic in every part when eaten by cats. The culprits are compounds called grayanotoxins, which can cause tremors, seizures, an abnormal heart rate and vomiting, among other symptoms. Fortunately, most cats recover well with prompt veterinary treatment.

4. Dieffenbachia (dumb cane)

This common leafy houseplant, recognisable by its two-tone leaves, is a familiar sight in hotel lobbies and sunny windowsills. If a cat bites into it, the plant releases needle-sharp, insoluble calcium oxalate crystals that cause mild to moderate irritation to the mouth and digestive tract. On rare occasions the crystals can cause the airway to swell, making breathing difficult. Most exposures are mild to moderate, though some can be serious.

5. Cannabis

It will come as little surprise that a cat chewing on a cannabis plant can become uncoordinated or sleepy. Medical cannabis, particularly CBD oil, is sometimes used deliberately in cats to help with inflammation, anxiety and pain, but CBD oil is a refined product that does not contain the psychoactive compound THC found in the raw plant. Chewing the plant itself can cause disorientation and sleepiness alongside vomiting, low blood pressure, seizures and even coma, and in rare cases cats have died from cannabis exposure. As legal recreational and medical cannabis becomes more widespread, keeping plants out of reach of cats matters more than ever.

What happens if your cat eats a toxic plant?

According to Dr Mahaney, treatment typically follows three main approaches:

1. Decontamination, using a vomit-inducing medication or a substance such as activated charcoal to remove toxins from the digestive tract.
2. Diuresis, giving intravenous or subcutaneous fluids to flush toxins and their by-products out of the body.
3. Monitoring, testing the cat's blood for markers of kidney failure and watching urine output to check the body is processing fluids normally.

Older cats often respond less well to treatment than younger ones, largely because kidney disease becomes more common with age, and kidneys that are already under strain find it harder to recover from a toxic exposure.

Cat-safe houseplants

Drawing on the ASPCA's extensive plant list, safe houseplant options include the spider plant, African violet, air plant (Tillandsia), parlour palm, staghorn fern, hen and chicks succulents (Echeveria), Christmas cactus and Phalaenopsis orchid.

Cat-safe cut flowers

Pet Poison Helpline suggests these safer alternatives for a vase of cut flowers: daisies (including gerbera daisies), orchids, roses, snapdragons, sunflowers and zinnias.

A frightening brush with lily poisoning, involving an overnight stay at the emergency vet for intravenous fluids and blood tests, along with a hefty vet bill, is often enough to change habits for good. Many owners end up keeping a "not safe for cats" list of foods, flowers and plants on the fridge, sticking afterwards to reliably safe choices such as roses and daisies.

Article content © Ravi Teja. All rights reserved.