Is Monstera adansonii Toxic to Cats?

Is Monstera adansonii toxic to cats?

Monstera adansonii is toxic to cats. The toxic principle is insoluble calcium oxalate crystals that penetrate the oral mucosa causing acute pain, burning and swelling. 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 herbivory.

What is Monstera adansonii?

  • Family: Araceae
  • Botanical name: Monstera adansonii
  • Plant type: Perennial
  • Common names: Monstera adansonii, Five holes plant, Swiss cheese plant, Adanson’s monstera
  • Toxicity: Toxic to cats
  • Toxic parts: All parts of the plant are toxic to cats
  • Severity: Mild to moderate
  • Toxic principle: Insoluble calcium oxalate crystals

Monstera adansonii is a climbing vine native to Central and South America. Its unique heart-shaped fenestrated leaves make it popular as an indoor house plant.

Monstera adansonii ‘Archipelago’ is a variegated variety that can sell for several thousand dollars.

Variegated Monstera adansonii
Variegated Monstera adansonii

Clinical signs

Most cats will stop chewing in response to the bitter taste and acute pain. Clinical signs are related to acute oropharyngeal pain due to contact with needle-sharp calcium oxalate crystals.

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

The response can look alarming to caregivers, however, symptoms are rarely life-threatening unless swelling develops, which can block the airways.

First aid

Give the cat a drink of something tasty such as tuna juice or milk to help flush the mouth. If the cat experiences swelling or difficulty breathing, seek immediate veterinary care.


Contact your veterinarian or pet poison helpline for advice. They may recommend a wait and see approach if the cat is not experiencing clinical signs

There is no specific antidote for Monstera adansonii ingestion and symptoms typically resolve quickly. Treatment is aimed at relieving symptoms and can include fluid therapy to correct dehydration and electrolyte imbalances due to vomiting, painkillers and manage airway obstructions in rare cases.


The only effective prevention is to avoid growing plants in areas where cats can access them.  Some pet owners will find their cats pay no attention to the plants, but others, especially kittens may be prone to chewing them. There are plenty of cat-safe plants for animal lovers and green thumbs.

Most cases of Monstera adanosii ingestion are mild and self-limiting. However, some plants, especially lilies and sago palms can be life-threatening to cats and should not be grown in homes with cats.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio