Oleander, Senecio (Nerium oleander)

(Nerium oleander)

Nerium-oleanderSenecio Oleander Flowers

Senecio Oleander (Nerium oleander) is an evergreen shrub or small tree in the dogbane familyApocynaceae, toxic in all its parts. It is the only species currently classified in the genus Nerium. It is most commonly known as oleander, from its superficial resemblance to the unrelated olive Olea. It is so widely cultivated that no precise region of origin has been identified, though southwest Asia has been suggested. The ancient city of Volubilis in Morocco may have taken its name from the Berber name oualilt for the flower. Oleander is one of the most poisonous of commonly grown garden plants.
Oleander grows to 6.6–20ft tall, with erect stems that splay outward as they mature; first-year stems have a glaucous bloom, while mature stems have a grayish bark. The leaves are in pairs or whorls of three, thick and leathery, dark-green, narrow lanceolate, 2.0–8.3 in long and 0.39–1.4 in broad, and with an entire margin. The flowers grow in clusters at the end of each branch; they are white, pink to red,  0.98–2.0 in diameter, with a deeply 5-lobed fringed corolla round the central corolla tube. They are often, but not always, sweet-scented.  The fruit is a long narrow capsule 2.0–9.1 in long, which splits open at maturity to release numerous downy seeds

Yellow-OleanderYellow Oleander Flowers and Buds

N. oleander is either native or naturalized to a broad area from Mauritania, Morocco, and Portugal eastward through the Mediterranean region and the Sahara (where it is only found sporadically), to the Arabian peninsula, southern Asia, and as far East as Yunnan in southern parts of China. It typically occurs around dry stream beds. Nerium oleander is planted in many subtropical and tropical areas of the world. On the East Coast of the US, it can be planted as far north as Virginia Beach, Virginia, while in California and Texas it is naturalized as a median strip planting.

Conditions of Poisoning:
Ingestion, Skin contact

Toxic Principle:
Cardenolides, Oleander has historically been considered a poisonous plant because its compounds exhibit toxicity, especially to animals, One leaf is fatal and will disrupt heart function, trigger circulatory failure and lead to death. Among these compounds are oleandrin and oleandrigenin, known as cardiac glycosides, which are toxic when ingested.

Clinical Symptoms:
Reactions to ingestion of this plant can include both gastrointestinal and cardiac effects. The gastrointestinal effects can consist of nausea and vomiting, excess salivation, abdominal pain, diarrhea that may or may not contain blood, and especially in horses, colic. Cardiac reactions consist of irregular heart rate, sometimes characterized by a racing heart at first that then slows to below normal further along in the reaction. The heart may also beat erratically with no sign of a specific rhythm. Extremities may become pale and cold due to poor or irregular circulation. Reactions to poisonings from this plant can also affect the central nervous system. These symptoms can include drowsiness, tremors or shaking of the muscles, seizures, collapse, and even coma that can lead to death.

Oleander sap can cause skin irritations, severe eye inflammation and irritation, and allergic reactions characterized by dermatitis.


 Lone Star English Setter Club provides this information
as a partial reference of the potential poisons that could harm your dog.
We are not veterinarian’s and DO NOT provide medical help.

 If you think that your animal is ill or may have ingested a poisonous substance,
contact your local veterinarian or
the ASPCA’s 24-hour emergency poisoning hotline directly