Bonsai trees can be toxic to cats, but toxicity depends on the species of bonsai. Many common bonsai trees such as Sago Palm, Azalea, Ficus, Wisteria, and Boxwood are toxic to cats if ingested, potentially causing symptoms like vomiting, excessive drooling, diarrhea, lethargy, breathing problems, and even seizures. The toxic effect is due to compounds in the plant that can harm cats' liver, digestive tract, or cause irritation. However, not all bonsai trees are harmful; some species like Juniper, Japanese Palm, Carmona, and Bamboo Palm bonsai are considered safe for cats. The risk arises mostly if the cat chews or ingests parts of the bonsai, so keeping bonsai trees out of cats' reach or in pet-free rooms, and providing safe distractions such as catnip, can help prevent poisoning. If a cat does ingest a toxic bonsai, immediate veterinary attention is advised, bringing along a sample of the plant if possible, to identify the right treatment.