Milkweed: The hidden toxin that Monarchs love

The Monarch Butterfly is the most familiar butterfly in North America. With their easily recognizable black, orange, and white wings they are quite hard to miss. There are many plants and flowers that will attract the Monarch and other butterflies but one plant that is a necessity for the Monarch is the Milkweed. While the Milkweed may attract Monarch Butterflies, it is a dangerous plant to have around our pets, our children, and even adults.

The name "Milkweed" comes from the plant's milky sap. Do not underestimate the sap from the Milkweed plant. It contains a toxin called cardiac glycoside. Cardenolides are a type of steroid found in all of the Milkweed species. This toxin is considered a "heart-arresting toxin" and in the same class that includes digoxin and acetyldigoxin. On top of the dangerous toxins, these plants can be invasive to underground rhizomes because they have horizontally growing rootstalks or stems.

Milkweed is toxic to dogs, cats, and other grazing animals. The plant does have a bitter taste but sometimes that is not enough of a deterrent to keep your animals away. A family pet that eats milkweed can have many medical problems and even death for the ones that consume 10 percent or less of their body weight. Medical problems that stem from the plant all depend on your pet’s body weight, the maturity of the plant, and which part of the plant was consumed. The most common medical issues that your pet can experience are vomiting, depression, weakness, and diarrhea. However, in some cases, these issues can be followed by seizures, difficulty breathing, rapid/weak pulse, dilated pupils, kidney or liver failure, coma, respiratory paralysis, and death.

Milkweed is also toxic to humans. Both children and adults can experience adverse effects from the plant. If a person gets Milkweed sap in their eye, just a small amount, this can cause burning, inflammation, loss/change in vision, sensitivity to light, corneal abrasions, and extreme pain. This is because the sap causes chemical burns in your eye. You must see an ophthalmologist immediately for proper care instructions and prescription eyes drops. Ingesting Milkweed, depending on the size of the individual, the amount consumed, and which part of the plant was consumed you could experience bloating, fever, difficulty breathing, dilated pupils, and muscle spasms and these results can be fatal. Special caution is needed for people that have younger kids that are very curious. A curious child likes to put things in their mouth or may touch their face a lot.  These actions may, accidently, have a child exposed to Milkweed sap and they can experience any of the medical problems listed above.

The USDA identifies over 76 species of Milkweed but only five are native to the Northeast region of The United States. The five species that are native to our area are the Common Milkweed, Swamp Weed, Butterfly Weed, Whorled Milkweed, and the Poke Milkweed.

While conservation of the Monarch Butterfly is very important to the environment, we must also think about the safety of our pets, our children, and adults that come in contact with the Milkweed plant. It is very important to do your homework on the plants you are thinking of planting in your backyard to be sure that everything and everyone will be safe. 

Written by: Brandy Reynolds