There are a number of plants that can be quite toxic to cats. The most commonly known of these are lilies, amaryllis, azaleas / rhododendron, bird of paradise, iris, daffodils, holly, ivy, tulips and sago palm. If any parts of these plants are nibbled on by your kitty, it’s best to call the vet straight away. Clinical signs of illness can vary from digestive system upset to kidney failure, heart failure, liver failure and even death.