Is Euphorbia Myrsinites Toxic to Dogs?

The Good: Unusual and Easy

• A fascinating plant structurally, donkeytail spurge looks more like the spine of a stegosaurus than the tail of a barnyard animal. The plant stems, rising about 8 inches from woody roots, are covered with tight spirals of oval, fleshy leaves that look like fish scales might if they grew on a cactus. Donkeytail spurge grows in almost any soil, including desert sands in U.S. Department of Agriculture plant hardiness zones 5 through 9. It tolerates deer and rabbit browse as well as pollutants.

The Bad: Invasive

• You may not even notice the green flowers that grow in spring from the stem tips of donkeytail spurge, but you can't miss the accompanying canary-yellow bracts. Those inconspicuous green flowers more than make up for their plain-Jane looks by their astonishing seed-production rate that allows the perennial to self-seed generously and expand its range with ease. The species has been declared a toxic weed in Oregon and Colorado and has become invasive in other Western states.

The Ugly: Toxicity

• Any friendly discussion of this plant's characteristics is sure to degenerate into a heated exchange of the types of damage it has inflicted. Donkeytail spurge has earned many enemies because of the toxicity of its milky sap. While Calflora lists the sap as causing minor dermatitis, the Web is full of tales of woe -- blisters, burns and swollen eyes that last for weeks -- by gardeners who have had the misfortune to touch the plant with naked flesh before they learned of the dangers.

The Conclusion: Dogs Beware

• Although the ASPCA does not list donkeytail spurge as toxic to dogs, it does not list it as nontoxic either. And the species makes other toxic-to-pets lists such as that put together by the Sweeten Creek Animal and Bird Hospital in North Carolina. Given the strong reaction some people experience just from touching the sap, it is prudent to keep dogs and other pets predisposed to chewing on plants, as well as children with similar traits, as far away from donkeytail as possible.