Monstera plants are indeed toxic to cats. The toxicity comes from insoluble calcium oxalate crystals present in most parts of the plant, including the leaves, stems, roots, and unripe fruit. When a cat ingests Monstera, these crystals cause irritation and micro-cuts in the mouth, throat, and digestive tract, leading to symptoms such as drooling, pawing at the mouth, swelling, vomiting, and difficulty swallowing. Although this irritation is uncomfortable, Monstera plants are not usually deadly to cats unless consumed in very large quantities, which is rare because the irritation tends to discourage further ingestion. Immediate veterinary attention is advised if a cat shows signs of Monstera toxicity.
In summary, Monstera should be kept out of reach of cats to avoid these adverse effects, though fatal poisoning is unlikely in most cases.
