2. COMMON BURDOCK

Arctium minus

(daisy family)

TOXICITY RATING: Low. Burs cause local irritation and possibly intestinal hairballs, and most animals avoid ingesting these plants. Serious illness and death are rare.

ANIMALS AFFECTED: All animals may be affected. Pastured animals and outdoor dogs are particularly at risk. Poultry may get burs lodged in the esophagus.

DANGEROUS PARTS OF PLANT: Burs.

CLASS OF SIGNS: Skin, eye, mouth, nose, and ear irritation; stomach irritation; hairballs.

PLANT DESCRIPTION: This familiar biennial weed (fig. 2) of waste places and roadsides grows from a fleshy taproot and produces large, heart-shaped, hairy leaves and red-violet flower heads surrounded by numerous hooked bracts that form a bur-like cup.

Burdock is often confused with cocklebur (a far more dangerous plant). Burdock burs are rounder and have softer, more Velcro-like hairs than cocklebur. Cocklebur burs are oblong and have hooked spines on the bur, and have, on the end of the bur, two spines which are larger and not as strongly hooked.

SIGNS: These burs, and those of cocklebur, crimson clover, rabbitfoot clover, sandbur, and buffalobur may lodge in the skin, eyes, ears, mouth, throat, or stomachs of grazing animals (and sometimes pets). Direct irritation may result, with swelling and pain, or the bur may form the center of a "hairball", a mass of plant matter, hair, and debris that can cause digestive tract irritation and possible obstruction. These burs also tend to lodge in the fur, manes, and tails of animals.

FIRST AID: Remove all visible burs (some may need to be cut out of the hair). If the irritation is minor, provide supportive care. If the eyes, ears, nose, mouth, feet, or hooves are involved, or in cases of digestive upset or inability to eat, a veterinarian needs to be contacted. Burs and hairballs may require surgical removal.

SAFETY IN PREPARED FEEDS: Only poor quality hay and feeds would contain these burs. If the number of burs is small or only in certain sections of the hay (which should be discarded), few problems may result. If there are many burs, especially if the animals are forced to eat these feeds, problems are likely to develop.

PREVENTION: Prevention consists of removing these plants from the pasture. Mowing is effective in reducing the number of flowers and burs that will develop.