Is Swiss Cheese Plant (Monstera Delicosa) Toxic To Cats?

Last Updated on September 26, 2021 by Julia Wilson

Is Swiss cheese plant toxic to cats?

Swiss cheese plant (Monstera delicosa) is toxic to cats. The toxic principle is insoluble calcium oxalate crystals which penetrate the oral mucosa causing intense pain and burning. Calcium oxalate crystals are produced by specialised cells known as idioblasts and are arranged in bundles known as raphides. They act as a defensive mechanism against plant-eating animals.

What is Swiss cheese plant?

  • Family: Araceae
  • Scientific name: Monstera delicosa
  • Common names: Tarovine, Fruit salad plant, Ceriman, Mexican breadfruit, Hurricane plant
  • Toxic parts: All parts of the plant are toxic to cats
  • Toxicity: Mild to moderate
  • Toxic principle: Insoluble calcium oxalate crystals

Swiss cheese plant is a popular ornamental climber native to the tropical forests of southern Mexico. Its large glossy leaves have fenestrations (holes), which give it its name. Swiss cheese plants are grown as decorative indoor plants, but can also be grown outside in warmer climates, however, they can take over if not kept in check.

Mature Swiss cheese plants produce a cream flower spathe followed by a tall edible fruit that is said to taste like bananas and pineapple.

Similar plants

  • Monstera Adansonii is also known as Swiss cheese plant. The leaves of Monstera Adansonii are considerably smaller than those of Monstera Delicosa.
  • Philodendron spp. has a similar appearance to the Swiss cheese plant, but they are different species of plant.
  • Rhaphidophora tetrasperma (mini monstera) has similar fenestrated leaves to Monstera Delicosa. The leaves of Rhapidophora tetrasperma grow to approximately the size of an adult hand.

What all three of these plants have in common is the toxic principle, which is insoluble calcium oxalate crystals.

Clinical signs

  • Oral pain and intense burning
  • Pawing at the mouth
  • Anorexia (loss of appetite)
  • Hypersalivation (drooling)
  • Soft tissue swelling
  • Vomiting
  • Difficulty swallowing
  • Swelling of the mouth and throat
  • Difficulty breathing (rare)

Most cats will stop chewing in response to the bitter taste and acute pain.

Warning: Seek urgent veterinary attention if lips or tongue become swollen or of there is difficulty breathing or swallowing.

First aid

Remove any remaining plant matter from the mouth and offer the cat a drink of milk or tuna water to help flush the mouth.

Treatment

Contact your veterinarian or pet poison helpline for advice. They may recommend a wait and see approach. If the cat is experiencing difficulty breathing, seek immediate veterinary attention.

There is no specific antidote for Monstera delicosa ingestion and symptoms typically resolve quickly. The goal of treatment is to relieve clinical signs which may include fluid therapy to correct dehydration and electrolyte imbalances due to vomiting.

Prevention

The only way to prevent Swiss cheese plant ingestion is to not grow it in homes with cats. Thankfully, most cats will show little interest in chewing Swiss cheese plants.

The good news is that in most cases of Monstera delicosa ingestion are mild and usually limited to the oropharynx. However, plants, such as lilies and sago palms can be life-threatening to cats and must be avoided altogether.