40. COMMON POKEWEED, POKEBERRY, POKEROOT, INKBERRY, POKE

Phytolacca americana

(pokeweed family)

TOXICITY RATING: Low.

ANIMALS AFFECTED: All animals may potentially be affected.

DANGEROUS PARTS OF PLANT: All parts, especially roots and seeds.

CLASS OF SIGNS: Gastrointestinal irritation (colic, diarrhea which may be bloody). Rarely: anemia, possibly death. Birth defects and tumors may also be possible.

PLANT DESCRIPTION: Pokeweed (fig. 40) is a tall (to 10 feet), smooth-stemmed, perennial herb with a large, fleshy taproot (fig. 40A). Stems are succulent, purplish, and bear alternate, lance-shaped, shiny leaves with smooth, curled margins. The small, white to greenish flowers hang in long, drooping, grape-like clusters. Each flattened, spherical, green berry turns dark-purple or ink-black and usually contains 10 seeds. Pokeweed commonly grows on recently cleared land, in open woods, barnyards, pastures, fence rows, and roadsides.

SIGNS: Animals do not voluntarily eat this plant unless there is no other forage available. If the animals are forced to eat pokeweed (especially if it has been incorporated into processed feeds), the primary signs relate to the irritant effects of the saponin toxins, in particular phytolaccigenin. Salivation, abdominal pain, diarrhea (which may become bloody) can be noted. Horses and ruminants do not exhibit vomiting, which is seen in humans, dogs, cats, and pigs. Signs usually resolve within a day or two. Only if large doses are consumed will the animal display more serious signs: anemia, alterations in the heart rate and in respiration, and in very rare cases, death.

Noted in the human literature but not well published in the veterinary literature is the mutagenic and teratogenic properties of pokeweed, that is the ability to induce mutations (and possibly cancer) and birth defects. For humans, even handling the plant is considered dangerous, so it would seem wise to not only prevent human contact with the plant, but animal contact as well. Despite this, the plant is eaten as a spring vegetable in the southern U.S. after cooking it first in several changes of water. Consumption of the plant is not advised.

FIRST AID: For gastrointestinal irritation, provide better feed and symptomatic care, and signs should abate in about 24 hours. Discard all feeds containing pokeweed, since the plant is never safe for consumption. For severely affected animals, or if it is known that a large amount was consumed, consult a veterinarian promptly for emergency care.

SAFETY IN PREPARED FEEDS: Reports are not clear, but consider pokeweed as unsafe in hay and other feeds.

PREVENTION: Pokeweed should be removed from pastures and barnyards. Exercise caution when doing so, since the plant is toxic to humans as well. Good pasture management, with mowing and weed removal, will suffice in keeping pokeweed under control.