Hairy vetch
General poisoning notes:
Hairy vetch (Vicia villosa) was introduced as a forage in Canada and has become successfully naturalized in parts of southern Canada. This plant causes poisoning in cattle, horses, and poultry. Various syndromes occur in cattle, including a dermatitis that resembles photosensitization in may respects, except that the skin lesions appear on pigmented skin as well. Mortality occurs in cattle and poultry (Panciera 1978, Kerr and Edwards 1982, Cooper and Johnson 1984).
Nomenclature:
Scientific Name: Vicia villosa Roth
Vernacular name(s): hairy vetch
Scientific family name: Leguminosae
Vernacular family name: pea
Vicia villosa Roth
Geographic Information
British Columbia, Manitoba, Nova Scotia, Ontario, Quebec
Notes on Poisonous plant parts:
This plant has occasionally caused poisoning when used as a forage for livestock (Cheeke and Schull 1985).
Toxic parts:
Leaves, seeds.
Toxic plant chemicals:
unknown chemical.
Animals/Human Poisoning:
Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.
Cattle
General symptoms of poisoning:
Anorexia, breathing, labored, coat, rough and dry, conjunctivitis, convulsions, death, diarrhea, pain, pneumonitis, restlessness, skin, peeling of, weakness, weight loss.
Notes on poisoning:
Two types of syndromes are suggested from the symptoms seen in cattle. The first syndrome is acute illness followed by death after ingesting raw seeds of hairy vetch. The animals were very restless, showed pain, experienced convulsions, and died. The second syndrome involves skin lesions, cough, respiration problems, and death after 2 weeks. Postmortem findings showed severe bronchitis with pneumonia, yellow- brown liver, and inflamed forestomachs (Panciera 1978, Cooper and Johnson 1984).
Horses
General symptoms of poisoning:
Conjunctivitis, mouth, edema of
Notes on poisoning:
Hairy vetch causes systemic granulomatous inflammation. Edema occurs especially around the lips and eyes. Conjunctivitis and corneal ulceration develops. The poisoning is most prevalant in mid to late spring as the hairy vetch reaches maturity (Anderson and Divers 1983).
Poultry
General symptoms of poisoning:
Breathing, labored, convulsions, incoordination, weight loss.
Notes on poisoning:
Feeding chicks experimentally on a diet of 30-80% hairy vetch seeds caused 20-40% mortality. Symptoms included weight loss, excitability, and sometimes violent convulsions (Cooper and Johnson 1984).
