Many common plants are toxic to pets, including sago palm tree leaves. The sago palm grows in warm climates but is a popular house plant, found in many homes and nurseries. The sago palm is the only type of palm tree considered poisonous to dogs, cats and other pets.
All parts of this plant, including the leaves, are considered poisonous to pets. The most dangerous part of the sago palm, however, is the seed or nut. The roots of the sago palm are another part of the plant that is especially toxic to pets.
According to the ASPCA, symptoms of ingesting the leaves or other parts of the sago palm include drooling, vomiting, diarrhea, a rapid heart rate, liver failure, coma or seizures. If not treated by a veterinarian, a pet that has eaten sago palm leaves could die. According to the Louisiana State University School of Veterinary Medicine, how the plant's toxins affect the liver are what makes it most dangerous, and vomiting is the first sign of danger. Later, more serious symptoms like jaundice, lethargy and a lack of appetite could be seen.
The sago palm resembles a large pineapple, with a thick, spiky base with long, feathery leaves emanating from the top. The leaves of the sago palm can grow up to 10 feet in length, and it is between these leaves that the very poisonous seeds grow.
The sago palm can also cause reactions in humans. The spiky bark on the base of the plant can prick the skin, resulting in a serious and sometimes painful rash. While some people do not experience a reaction at all, others can have a severe allergic reaction.