Calathea plants are non-toxic to cats. According to the ASPCA and multiple reliable sources, Calathea plants do not contain any harmful compounds that could poison cats. However, while the plant is safe, if a cat eats a large quantity of Calathea leaves, their fibrous texture may cause mild gastrointestinal discomfort, including vomiting, diarrhea, drooling, and loss of appetite. In such cases, veterinary care is advised. It is generally recommended to keep plants out of pets' reach to avoid overconsumption and damage to the plants.