Other common names include Beggar’s Lice and Dog Bur. These are the innumerable, tiny, sharp velcro-burs that land on your dog as well as your socks and sleeves! Houndstongue is considered a noxious weed as it causes a loss of grazeable pasture, and is quite toxic to horses and cattle. It contains pyrrolizidine alkaloids, which are known to be toxic to goats as well. However, houndstongue is nearly impossible to avoid on many grazing contracts and with supplemental protein my goats eliminate it during the summers and seem to do just fine. Burs be gone!