Is a Horsetail Plant Dangerous to Dogs?

Horsetail (Equisetum arvense) is not poisonous to dogs, but is toxic to livestock. Sheep, goats and cattle exhibit signs of poisoning after eating fresh horsetail. Ingesting dried horsetail leads to poisoning in horses. Signs of horsetail poisoning are weakness, weight-loss, clumsiness, breathing difficulties and in severe cases, death.

Plant Horsetail

A plant for pond edges, bog gardens and other wet sites, horsetail (Equisetum hyemale) grows in stands of bamboo-like, dark green stems. Also called scouring rush, horsetail is hardy in U.S. Department of Agriculture plant hardiness zones 3 through 11, and is a member of an ancient plant family that dates back 350 million years, notes the Missouri Botanical Garden. Plant horsetail in a container, with drainage holes, that's just large enough to accommodate the plant's root ball. Place a sheet of fine mesh, such as screen mesh, over the drainage holes to prevent horsetail rhizomes from growing through them, and spread a layer of general purpose potting soil over the mesh. Place the horsetail in the container. Providing year-round color and structure in wet, full-sun and partial-shade sites, horsetail tolerates water to a depth of 4 inches over its roots. Horsetail grows 2 to 4 feet tall and spreads indefinitely in favorable conditions. Check the horsetail monthly, at least, for rhizomes climbing over the container rim and stems with cone-like, spore-producing heads, which usually appear in spring. Wipe the pruning shear blades with rubbing alcohol again after use.