Cats and poisonous plants, part one: Indoors

An off the cuff Twitter conversation with a friend of mine the other day prompted me to create a public service post for my cat-loving readers. She hadn't known that so many plants, both those grown indoors and those in our gardens, are toxic to cats. I've written about this before, but it bears bringing to other cat-loving plant people's attention on a regular basis.

Cats do like to get into things, although usually those are food-related items such as cans of soup. Yes, this is Mungus. If someone is doing something bad in our house, it's usually Mungus.



Disclaimer 1: I am not a dog person, so I don’t tend to think about what dogs might do. However, I do strongly advise that people with dogs exercise even more caution with plants, both indoors and in the garden, as they’re more apt to try a plant that isn’t good for them than cats are, at least in my experience. Disclaimer 2: I am not a veterinarian, and all information posted here is drawn from talking to veterinarians plus my own research over the years.

Anthuriums should be kept well out of reach of curious kitties.
Why do cats chew on plants? My answer to that is the answer I use for many things pertaining to cats—because they can. Maybe because they’re bored, mischievous, curious; maybe they’re lacking something in their diet.

Hyacinths, tulips, lilies, narcissus are all highly toxic to cats. 
There are varying degrees of plant toxicity: some will cause a little nausea, diarrhea or drooling, much as some of ours do when we give them their regular worm medication. Others are much more serious, causing renal failure, depression, inability to eat or drink, heart failure, and ultimately, death.

What should you do to protect your cats from toxic plants such as clivia, another lily relative?

The tubers of cyclamen, like bulbs of lilies, clivia, etc, are especially toxic, causing heart arrhythmia, seizures, and death if consumed in large enough quantities.

Indoors, if you’re a person with a lot of flowering or foliage plants, try to put them places where the cats can’t easily get at them. I have a cycad up on top of my filing cabinet, and a plumbago that one of our finds quite irresistible in another (relatively) inaccessable location. I've never had a cat try to eat begonias, cyclamen, zonal geraniums (pelargoniums) or amaryllis, but it's still good to be cautious.

The common zonal geranium (Pelargonium) can cause vomiting, depression, and even anorexia. These plants are quite pungently scented, and that seems to deter my furry brood from even checking the plants out.

If you have cats that are intent on chewing on plants, you might want to grow some cat grass for them, particularly in winter; a number of seed companies sell packaged grass seeds that are safe for cats to dine on. I've done this and had the furballs eat the grass quite happily.

I personally don't recommend trying to grow catnip indoors because if you have hardcore catnip addicts like we have, they'll eat it right down to the roots...climb up on anything to reach the pot, or chew through a bag to get at it. Hardcore, I tell you. (Mungus is eating a big dried flower clump of a type of catmint here. When he escapes from the house, he heads for this plant every time.)

Both calla lilies (Zantedeschia) and Caladium can cause intense irritation of the mouth, lips, and tongue, as well as vomiting and problems swallowing.

Outdoors, the answer is easy: don’t let your cats outdoors unsupervised (the birds and other wildlife will thank you, and the cats will thank you for not letting them get hit by vehicles or attacked by coyotes, etc), or else put them in an enclosed area where there is only pesticide-free grass or other non-toxic plant material. If you’re able to harness train your cat, that works fine as well. In all the years we have had cats, including many former cats who used to go outdoors unsupervised on our rural property, we’ve never had one try to eat something like hellebore, monkshood, delphinium or lilies, all of which I’ve grown for years.

The tubers of begonias are the most toxic part, but the foliage could be very tempting for a naughty kitty to try.

The American SPCA has a very good list of plants that are toxic as well as a list of non-toxic plants to cats on their website. It lists plants by a common name, with more common names and the botanical name included in the category, but you may not necessarily call a plant by the same common name as your neighbour down the road or in another province/state. Both lists are on the same page, which is a bit annoying--you need to scroll down about halfway to find the plants that aren't toxic.

Some of the more dangerous plants include:
Lilies of all kinds, including Easter lilies and Oriental lilies as cut flowers
Amaryllis, hyacinths, clivia and other lily-relatives.
Sago palm (aka Cycad)
Cannabis. Yes, that plant. I could care less about whether people use it or not, but it's extremely poisonous to cats.
Dieffenbachia
Indoor (ornamental, evergreen) azaleas
Ivies such as Hedera helix
Hydrangeas (the puffy blue or pink ones so popular around Easter.)

Always do some research to find out whether that plant you're tempted by is a good one to have in the house with naughty furball friends. I suppose the same goes for children, but this isn't a mommee blog! 

 However, you still might want to think about locations with the houseplants: I have numerous (nontoxic) African violets (Saintpaulia) around the house, and if they’re in a window easily visited by the cats, the plants invariably look like lint-rollers, festooned with cat hair in a variety of colours, but commonly orange, white and grey. They ignore the (highly toxic) amaryllis sitting beside the violets, but they rub up against those silky African violet leaves every time!

If you suspect your cat has eaten a poisonous plant, call the ASPCA poison control  (in the USA, 1-888-426-4435) or your local veterinarian immediately. (If there's a Canadian counterpart with the SPCA, I can't find it, so Canadians, call your veterinarian! ) Take a leaf or flower of the plant with you when you go to the clinic, in the event that you're uncertain about the plant's identity.