Poisonous Plants Leanne Stevenson Miami County Agriculture Extension Agent

Poison Any substance which, when taken into the system, acts injuriously, in a manner neither thermal nor mechanical, tending to cause death or serious detriment to health.

In General More than 700 plants toxic to animals Economic losses #1 reason for calls to poison control centers Chemicals in plants are natural defense Best Treatment – prevention

Can you tell by looking at a plant if it is poisonous? NO

Suspect Plant Families Philodendron family (Araceae) Cactus family (Cactaceae) Tomato family (Solanaceae) Spurge family (Euphorbiaceae)

Levels of Poisoning Chronic - Over a period of time. Can refer to prolonged or repeated exposure to toxins or to the progression of clinical signs. Acute - A rapid, severe onset of signs.

Classes of Poisons Poisons acting on the brain Poisons acting on the spinal cord Poisons acting on the heart Vegetable irritants

Houseplants

Amaryllis Houseplant Bulbs and seeds are toxic Humans Gastrointestinal problems vomiting, diarrhea

Caladiums & Dieffenbachia Houseplant All parts Humans and pets Ingestion causes intense burning, swelling and irritation of the mouth, lips and throat

Easter Lily Houseplant or ornamental All parts Humans, cats, livestock Dizziness, stomach pain, collapse, fatal to livestock

Oleander Ornamental shrub Extremely toxic Livestock, pets and humans Gastroenteritis, diarrhea, abdominal pain, sweating and weakness

Landscaping Plants

Azalea, Rhododendron Shrub Entire plant Livestock, pets and humans Nausea, vomiting, weakness, dizziness, breathing difficulty, coma

Castor bean Ornamental herb Various parts of the plant – particularly in the seed One of the three most toxic plants All livestock, pets and humans 6 seeds can kill a horse 1-2 seeds can kill a child

Delphiniums and Larkspurs Perennial Young leaves and seeds Pets, humans, cattle, and can effect horses Nervous symptoms, nausea, depression and even death

Foxglove Biennial plant All parts – most toxic just before the seeds ripen Cats, cattle, dogs, goats, horses, humans Dizziness, vomiting, irregular heart beat, and delirium or hallucinations. Can be fatal at any time.

Lantana Annual flower, warm climates spreading shrub All parts are quite toxic Cattle, sheep, horses and humans Gastric, vomiting, diarrhea, circulatory collapse

Lily of the Valley Perennial flower All parts are extremely toxic Humans, cats, dogs, goats Nausea, vomiting, diarrhea, irregular heartbeat and pulse, mental confusion – can lead to coma and death

Red Maple Ornamental tree Leaves, especially when fallen, damaged, or wilted Horses only Breathing difficulties, jaundice, dark brown urine, death

Rhubarb Garden plant Low, unless animals are fed the leaves intentionally Cattle, swine, sheep and goats Staggering, trembling, breathing difficulties, weakness, diarrhea, increased drinking and urinating, death

Black Walnut Natural and ornamental tree Moderately toxic, depending upon length of exposure Horses, dogs, possibly other animals Laminitis, breathing problems, gastroenteritis

Yew Ornamental Shrub All parts extremely toxic, death is likely All animals-livestock, pets, humans and birds Sudden death is the typical sign. Occasionally: breathing problems, trembling, weakness, heart problems, stomach upset.

Plants in Nature

Black Locust Shrub or tree Roots, bark, sprouts, seed pods and/or trimmings Horses, cattle, sheep, poultry and humans Weakness, posterior paralysis, depression and loss of appetite

Common Cocklebur Annual herb Toxin concentrated in the seeds and seedlings Vomiting and gastrointestinal irritation with occasional diarrhea Swine mostly – chickens and other livestock

Hemp Dogbane Native perennial All parts- particularly tender shoots. Can be in hay Horses, cattle, humans, sheep, cats, dogs, goats Heart stimulant, increased temperature and pulse, pupils dilated. Can result in death.

Horsenettle Perennial, thorny herb Berries most toxic, leaves to a lesser degree Mostly cattle, humans, rodents Sometimes sheep, horses, goats Irritation of the mouth, gastrointestinal lesions, unthriftiness, jaundiced mucous membranes, abdominal dropsy and constipation

Jimsonweed Annual All parts, green or dried are poisonous – especially seeds Cattle, swine:primary Horses, poultry, goats, dogs and humans: possible Cattle –.5 to 1# Weak, rapid pulse and heartbeat

Milkweed Perennial herbs All parts are toxic fresh and dried Cattle, sheep, goats, horses and poultry 2% of body weight Staggering, depression, weakness, labored respiration and dilated pupils Eventual coma and death

Poison Hemlock Biennial Herb All parts are toxic, but the seeds are the worst Livestock, poultry and humans Gastrointestinal irritation, nervousness, trembling, staggering, coldness of the extremities, slow heartbeat and eventually coma and death

Pokeweed Perennial herb Young leaves often used as cooked green Older leaves quite poisonous Root most poisonous – other parts contain smaller amounts of toxins Cattle, horses, swine and man Severe gastroenteritis w/ cramping, diarrhea and convulsions Can be fatal Treat with gastrointestinal protectives and sedatives

Myths & Potentially Poisonous Plants

Poinsettia No part of these holiday beauties is toxic to either people or pets Tastes extremely bitter and could cause stomach upset The milky sap can trigger allergic reactions and skin irritations.

Nitrate Toxicity

What to do… In case of Emergency – identify the plant, determine how much was eaten, and contact the poison control center. Watch for adverse symptoms Take the plant with you to the hospital or veterinarian.

Poison Control Centers For humans: Refer to handout For pets: ASPCA National Animal Poison Center ASPCA-NAPCC

Additional Resources

Know whether you have plants in your house, yard or property that are toxic. Know the signs of toxicity. Use risk management techniques to decide what to do with your toxic plants. Have poison control numbers handy.