Pothos is toxic to cats. The plant contains insoluble calcium oxalate crystals, which can cause irritation and injury to a cat's mouth, throat, and stomach if ingested. The crystals can penetrate soft tissues, leading to symptoms such as drooling, vomiting, difficulty swallowing, mouth and throat pain, and gastrointestinal upset. While it is not typically fatal, ingestion can cause significant discomfort and health issues requiring veterinary attention. It is advisable for pet owners to keep pothos out of reach of cats to prevent accidental ingestion and ensure their safety.