The Novice Gardener: Will a "Poisonous" Plant Really Kill Your Cat?
My cat, Minou, eats houseplants and she's still alive. I don't let her eat them, but she eats them. In the turf battles I fight with my cats, I prioritize no scratching the sofa over no eating the houseplants, and since she seems fine after every green snack, I've come to wonder if houseplants are "toxic" to her like bourbon is "toxic" to me; poisonous, but delightful, and harmless enough in small doses.
My skepticism started with poinsettias. First, Minou tasted them, then she ate them, then...nothing happened. These were poinsettias we're talking about—the blood red angels of death that incredulous observers of my cat-rearing methods can't believe my cat has survived.
Is it any wonder I've come to view some of the more hysterical houseplant toxicity lists as alarmist Internet click bait?
Of course, some plants are poisonous to pets. But which ones? To set the record straight, I interviewed Dr. Tina Wismer, medical director of the American Society for the Prevention of Cruelty to Animals Animal Poison Control Center and did a little research of my own. Read on for the details:
N.B.: What about you? Has your cat (or dog) eaten a so-called poisonous plant and lived to tell (or bark) the story? Tell us about it in the comments below.
Photography by Meredith Swinehart except where noted.
Above: Minou licks her lips at the sight of a false aralia.
As anyone with animals or children or spouses or roommates knows, you have to pick your battles when it comes to perfection at home. But scratching the sofa doesn't kill cats—and eating the houseplants could. I don't know everything my cat has eaten, but I know \she's sampled the leaves or petals of poinsettias, asparagus fern, English ivy, selaginella, tulips, begonia, winterberry, hypoestes, roses, hydrangea, and cyclamen, to name just a few.
Here's what Dr. Tina Wismer, medical director of the ASPCA Animal Poison Control Center, has to say on the subject:
If Minou has eaten potentially poisonous plants, why does she seem to be just fine?
Dr. Wismer: Every plant is going to have a different amount of toxins in it. For example, when selectively breeding for flower color we may increase or decrease the toxicity of a plant. Plants that are under more stress (insect damage, drought, etc.) may have increased amounts of toxins in them. Also the amount of toxins can change during the growing cycle.
Above: Lucky for Minou, false aralia is non-toxic to dogs and cats.
Okay, so first things first: Which plants are toxic or nontoxic to cats and dogs?
Catster has a comprehensive list of Plants and Foods that Are Poisonous to Cats. For nontoxic, JaneA Kelly outlines 10 Cat-Safe Plants for Your Balcony Garden, and for at least one toxic plant, our Ask-a-Vet columnist Dr. Eric Barchas has Take It from a Vet: Lilies Are Toxic to Cats. In terms of edibles, Catherine Holm wrote What Greens Are Safe -- or Not Safe -- for Your Cats?
The list includes many plants commonly known to be poisonous—including castor bean, oleander, and yew—plus some plants that aren't yet common perpetrators but whose poisoning incidences are on the rise, including marijuana.
The ASPCA also has a pet poison call center, and information on What To Do If Your Pet Is Poisoned.
Above: In an earlier installment of The Novice Gardener, I tried to embrace houseplants. There is very little left of my favorite, the begonia, after three months of living with Minou. Even though the ASPCA Database includes begonia as toxic to both dogs and cats, she's continued her snacking.
If the begonia is supposed to make Minou feel sick, why does she keep going back for more?
Dr. Wismer: Many pets do not seem to be able to correlate the vomiting or other problems they are having with the eating of the plant material. If the vomiting occurs hours after the animal ingests the substance, they won’t know why they are feeling sick and would likely ingest that toxin again without making the connection.
Above: Cyclamen is included on the ASPCA's list of 17 Poisonous Plants, noted as potentially causing intense vomiting and even death.
How did Minou survive eating cyclamen, the potentially fatal Christmas tuber?
Maybe because she didn't eat the actual tuber. According the to ASPCA, chemical compounds that are toxic to pets can be concentrated in different parts of the plant—sometimes the roots, sometimes leaves, flowers, or seeds. In cyclamen, the poisonous compound called cyclamine is most concentrated in the root, or tuber, portion of the plant. Minou left a few teeth marks in the flower petals, but left the rest of the plant alone. Regardless, I won't keep any more cyclamen in the house.
Above: An orange Lillium superbum from Vita's Sunset Garden. Photo by Kendra Wilson for Gardenista.
Which plants are deadliest to cats?
Dr. Wismer: These are the plants where one bit can kill or cause serious problems. For cats, lilies—members of the true lily family (Hemerocallis sp., Lilium sp.). While the poisonous component has not yet been identified in these plants, it is obvious that with even ingestions of very small amounts of the plant, severe kidney damage could result.
Which plants are deadliest to dogs?
Dr. Wismer: For both dogs and cats, it's sago palm. The seeds or "nuts" of the sago palm contain the largest amount of toxin. The ingestion of just one or two seeds can be very serious, including vomiting, diarrhea, depression, seizures, and liver failure.
Above: As I planted an asparagus fern last November, Minou was lurking. It turns out the asparagus fern is also toxic to both dogs and cats—potentially causing allergic dermatitis and vomiting or abdominal pain—but luckily, it's a plant Minou has largely ignored.
Above: My smaller cat (and Minou's daughter), Reine, couldn't be less interested in houseplants—she never eats them—which makes me wonder:
Are houseplants the biggest household poison problem for pets?
Dr. Wismer: Houseplants seem to be the biggest issue for cats, but for dogs things like chocolate and human medications (ibuprofen, acetaminophen) can be more serious. It’s best to pay close attention to everything! Don’t leave anything out on countertops unattended and be sure to checkASPCA.org before purchasing any plants for your house or yard.
The Poison Control Center also lists the Top Pet Toxins of 2012. Topping the list for the fifth year in a row is prescription medication for humans.
Is there anything I can do to stop my pets from chewing on plants?
I sprayed Grannick's Bitter Apple, a taste-deterrant spray, on all my houseplants. Minou didn't like the taste, but I found that I needed to reapply the spray every day in order for it to keep her at bay. (I fail to water my plants on a weekly basis, so I definitely failed to spray them every day.) I also found that the more porous the plant, the more its health suffered from the spray: I don't think it was healthy for the ferns, moss, and begonia.
It seems that the best solution is avoidance. I knew that Minou would continue to nibble on the begonia until it died, and its toxins are not good for her. So I composted the begonia and planted cushion moss to live alongside three tiny hypoestes and a creeping pilea (Above), three plants listed among the non-toxic on the ASPCA list. Now the entire arrangement is non-toxic to dogs and cats.
As for the poinsettias, the ASPCA lists poinsettias as toxic to both dogs and cats, but "generally overrated in toxicity." I stopped buying poinsettias after that first Christmas, mainly because poinsettias peppered with cat bite marks and bleeding milky white sap just aren't as pretty as poinsettias that have been left alone.
I've sworn off cyclamen and I realize now that it's just plain lucky that I'm not especially fond of lilies.
Read more adventures of the Novice Gardener in 10 Tips for the Beginning Gardener—What I Learned In Year One and Houseplants for a Hater.
Learn more about your cat with Catster: