Eucalyptus, a plant that belongs to the family Myrtaceae, is toxic to cats. Eucalyptus is found in essential oils and is toxic to other domestic animals, including dogs and horses, say experts at the American Society for Prevention of Cruelty to Animals, or ASPCA. If owners discover their cats have eaten eucalyptus, they should immediately contact their vets or the ASPCA's poison control center.
Signs that a cat may be suffering from eucalyptus poisoning include salivating, gastrointestinal distress, depression and weakness, say experts at ASPCA. As with humans and other animals, some cats have more severe reactions to eucalyptus than others.
Since eucalyptus and many other common household and yard plants may poison cats, prevention is the best remedy. Cat owners should keep potentially harmful plants out of their homes and gardens because cats could inadvertently eat the plants. Other plants that may poison cats are amaryllis, crocus, rhododendron, chrysanthemum, cyclamen, marijuana, oleander, Spanish thyme, yew and several types of lilies.
Sometimes, only parts of plants are toxic, while others are harmless. This is true for tulip and narcissus plants, which have poisonous bulbs. However, owners should assume that all parts of plants identified as poisonous may harm their felines. If people suspect plant poisoning, they should try to identify the plant before taking the cat to the vet, as veterinarians prescribe treatment according to the type of plant.