Yes. The ASPCA lists Monstera deliciosa as toxic to both cats and dogs in its Swiss Cheese Plant and Ceriman entries, and names insoluble calcium oxalates as the toxic principle. NC State Extension lists Monstera adansonii as toxic to pets as well. If your pet chewed or swallowed any, call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435.

For growing it, see the Monstera deliciosa care guide.

What happens if a cat or dog eats monstera

The ASPCA's Swiss Cheese Plant entry, which is Monstera deliciosa, lists these clinical signs for cats and dogs: "Oral irritation, intense burning and irritation of mouth, tongue and lips, excessive drooling, vomiting, difficulty swallowing." Its Ceriman entry, for the same species, words them a little differently: "Oral irritation, pain and swelling of mouth, tongue and lips, excessive drooling, vomiting (not horses), difficulty swallowing." That entry also lists the plant as toxic to horses.

NC State Extension's Plant Toolbox page for Monstera deliciosa lists the bark, flowers, fruits, leaves, roots, seeds and stems under "Poison Part," and rates the poison severity as "Low." It also notes that "contact with cell sap may cause skin irritation."

What to do if your pet ate some

Call your veterinarian, or call the ASPCA Animal Poison Control Center. The ASPCA's instruction is: "If you think your pet may have ingested a potentially poisonous substance, call (888) 426-4435." The same page notes, "A consultation fee may apply."

Have the plant's name ready. The botanical name (Monstera deliciosa or Monstera adansonii) is clearer than "monstera" or "Swiss cheese plant," and a photo of the plant helps if you are not sure which one you have. Then follow the instructions the veterinarian or poison control specialist gives you.

Is every monstera toxic, including Monstera adansonii?

The ASPCA entries above cover Monstera deliciosa. For other species, NC State Extension's Plant Toolbox is the source:

  • Monstera adansonii. NC State's Monstera adansonii page says, "This plant is toxic to humans and pets if ingested." It lists cats and dogs under "Problems," gives the toxic principle as calcium oxalate crystals and the symptoms as "inflammation of the mouth, throat, eyes, and digestive tract, vomiting, drooling, and loss of appetite."
  • The genus. NC State's Monstera siltepecana page states, "Plants in this genus are toxic if ingested," and, for that species, "If ingested, the plant is toxic to cats, dogs, and humans."

The common names overlap. The ASPCA's Swiss Cheese Plant entry is M. deliciosa, but NC State also lists "Swiss Cheese Plant" and "Swiss Cheese Vine" among the common names of M. adansonii. NC State lists "Split-leaf Philodendron" as a common name of M. deliciosa, and the ASPCA's Swiss Cheese Plant entry lists "Cutleaf Philodendron" among its additional common names. The botanical name on the plant tag is the clearer guide. For telling the two species apart, see Monstera deliciosa vs. Monstera adansonii and the monstera care guide.

Keeping a monstera in a home with pets

  • Choose the room first. A large M. deliciosa is usually a floor plant, so its lower leaves sit at pet height. A room your pet doesn't use is the most reliable spot.
  • Watch the aerial roots. They often hang low, and NC State lists "Roots" among the poison parts of both M. deliciosa and M. adansonii.
  • Pick up fallen leaves and trimmings before a pet finds them.
  • Use a hanging planter for smaller species. NC State describes M. adansonii as a smaller plant; it can go in a hanging planter, but trim any vine that grows within reach.
  • Wear gloves when pruning. NC State notes that sap contact may cause skin irritation (M. deliciosa, M. adansonii).
  • Don't rely on deterrents. No placement or deterrent spray guarantees that a pet will leave a plant alone. If your pet is a determined chewer, a plant the ASPCA lists as non-toxic is the simpler choice.

Houseplants the ASPCA lists as non-toxic

The ASPCA's plant list adds a caveat that applies to every plant: "the consumption of any plant material may cause vomiting and gastrointestinal upset for dogs and cats." With that in mind, these houseplants have ASPCA entries listing them as non-toxic to dogs and cats:

For longer lists, see plants safe for cats, plants safe for dogs and the toxic plant directory.

Frequently asked

Is monstera toxic to dogs?
Yes. The ASPCA's Swiss Cheese Plant and Ceriman entries both list Monstera deliciosa as toxic to dogs and cats. The toxic principle is insoluble calcium oxalates, and the listed signs include oral irritation, excessive drooling, vomiting and difficulty swallowing.
Is Monstera adansonii toxic to cats?
Yes. NC State Extension's Plant Toolbox says Monstera adansonii is toxic to humans and pets if ingested and lists cats and dogs under 'Problems.' It gives calcium oxalate crystals as the toxic principle.
Is it safe to have a monstera in a house with cats?
The ASPCA lists Monstera deliciosa as toxic to cats, so no spot in the house makes it risk-free. If you keep one, put it in a room your cat doesn't use or well out of reach, and pick up fallen leaves and trimmings. If your cat chews plants, a plant the ASPCA lists as non-toxic, such as a parlor palm, is the simpler choice.
What should I do if my cat ate a monstera leaf?
Call your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435. The ASPCA notes that a consultation fee may apply. Have the plant's botanical name ready, such as Monstera deliciosa.
Is split-leaf philodendron the same plant as monstera?
The name is used for Monstera deliciosa: NC State Extension lists 'Split-leaf Philodendron' as one of its common names, and the ASPCA lists 'Cutleaf Philodendron' among the additional common names on its Swiss Cheese Plant entry, which it classifies as toxic to cats and dogs.

Sources: ASPCA: Swiss Cheese Plant, ASPCA: Ceriman, ASPCA Animal Poison Control Center, ASPCA: Toxic and Non-Toxic Plants, ASPCA: Parlor Palm, ASPCA: Calathea, ASPCA: Spider Plant, ASPCA: Boston Fern, NC State Extension: Monstera deliciosa, NC State Extension: Monstera adansonii, NC State Extension: Monstera siltepecana