Is Monstera toxic to cats and dogs?

If you’re not just a houseplant enthusiast but also a pet owner, things can get a bit complicated. You have to make sure your plants and pets are compatible: some greenery is toxic. Since most types of pets are known to take the occasional bite out of our plants, that can be problematic. So how about the popular Swiss cheese plant? Is Monstera toxic to cats? How about dogs and other pets?

Keep reading for everything you need to know about Monstera toxicity.

Is Monstera toxic to cats and dogs?

You’d think there would be a straight ‘yes or no’ answer to this question, but there really isn’t.

The genus Monstera, a popular aroid houseplant, is listed by the ASPCA as being toxic. However, it can be argued that this isn’t really the correct term. The reason this genus is branded as toxic is because all of its parts contain calcium oxalate crystals – more on what those are below.

Calcium oxalate crystals are highly irritating, especially to the mouth and even the stomach when ingested. If your cat takes a bite out of your Monstera (whether it’s a Monstera deliciosa, a Monstera adansonii or one of the other species), it probably won’t have a great time. This stuff can apparently be seriously painful (I haven’t tried!).

The thing is, although your cat or dog might show signs of pain and irritation after taking a bite out of your Monstera, it should otherwise be fine. The only real danger is if an uncommon swelling reaction occurs. There is no toxin in its system slowly working to shut its body down: just a nasty sensation on the tongue and throat area.

Ginger cat with Monstera deliciosa leaf | Is Monstera toxic to cats and dogs?

So, not toxic. But is it dangerous?

Whether you want to call it ‘toxic’ or just ‘irritating’, the real question is of course whether Monstera is dangerous or not. Although I’d personally try to keep this houseplant out of my pet’s reach, there is no real reason to panic if it does get its paws on it.

After the pain from the initial bite, there’s pretty much no way it’ll go for another one, meaning the real danger this plant poses is limited.

Aside from the above, Monstera leaves aren’t really the kind of dangly-stringy sort that cats like, so it’s probably not likely your feline friend will try to take a chomp out of them in the first place. It’s probably more likely to go for your spider plant or string of hearts. Dogs, on the other hand – always a gamble.

Tip: Although the ‘toxic’ label for Monstera and other calcium oxalate-rich houseplants might be overly strong, keep in mind that this doesn’t go for all species that are referred to as such. Some really are highly toxic, like lilies. Always check before buying!

Corgi dog in small white tipi tent in living room surrounded by houseplants

Calcium oxalate crystals

Now that we’ve clarified some things about Monstera toxicity, let’s pull out some scientific sources and briefly go into the whole calcium oxalate crystal business. What is this stuff?

  • Calcium oxalate crystals are also what causes kidney stones.
  • Calcium oxalate crystals are created inside the plant’s cells and can be needle shaped (called raphids). Sometimes they even have barbs (Franceschi, 2001). No wonder they hurt!
  • It’s not entirely sure if the calcium oxalate in plants is meant to regulate calcium levels, deter herbivores or if it has another function (Franceschi & Horner, 1980).
  • Some popular fruits and vegetables contain calcium oxalate crystals. Spinach in particular has high concentrations.
  • Quite a number of houseplants contain large enough concentrations of calcium oxalate crystals to be irritants. Dieffenbachia is the most well-known culprit and can hurt pretty badly. Syngonium, Philodendron, Alocasia… all these popular plants are on the list.

All in all, it’s not pleasant stuff to have touching your mucous membranes. And yep, there have been cases in humans as well (Pang, Ng & Lau, 2010).

But is it deadly? Nope, unless there is prolonged exposure or a reaction that causes excessive swelling, all should be well after treatment.

Monstera Adansonii, a popular houseplant.
The information in this article applies to both the large Monstera deliciosa and the smaller Monstera adansonii, which is pictured here.

Help, my pet nibbled my Monstera!

Will my pet be okay?

Yikes! If your pet managed to reach your Monstera and chomp it, first off, don’t panic. As we discussed, your furry friend will live. Here’s what you do:

  • Take a look at your pet and the inside of its mouth. Keep an eye out for redness and swelling. If all seems well, you probably don’t have to do anything.
  • Do you see irritation or does your pet appear to be in pain? Offer water or something more enticing to stimulate drinking. This can wash the crystals from the mouth. You can also try rinsing out its mouth yourself.
  • If your pet is still clearly suffering after this, or if you’re worried the swelling might block its airway, head to the vet. They might administer a painkiller and offer additional treatment.

Tip: The above basically applies to kids as well. After having some water or milk, the pain won’t be gone, but things should usually be fine. If you’re really worried, you can always ring a doctor.

Will my plant be okay?

Although it’s pretty clear by now that your Monstera is perfectly capable of defending itself, the sight of a maimed plant can be worrisome.

No worries: your Monstera will be absolutely fine. Unfortunately the damaged foliage won’t recover, so you can remove it if you find it unsightly. Other than that, the plant should keep growing as usual.

If you have any more questions about Monstera toxicity or if you want to share your own experiences with this popular houseplant, don’t hesitate to leave a comment below. Happy planting! 🌱


Franceschi, V. (2001). Calcium oxalate in plants. Trends in Plant Science6(7), 331.

Franceschi, V. R., & Horner, H. T. (1980). Calcium oxalate crystals in plants. The Botanical Review46(4), 361-427.

Pang, C. T., Ng, H. W., & Lau, F. L. (2010). Oral mucosal irritating plant ingestion in Hong Kong: epidemiology and its clinical presentation. Hong Kong Journal of Emergency Medicine17(5), 477-481.