perilla
mintAnnual herb, .2 to .6 m tall, freely branched. Leaves opposite, purple or green, ovate, 5 to 13 cm long, 4 to 10 cm wide, coarsely serrate, crushed leaves and stem with a strong pungent odor. Flowers small, white to purple, with a ring of hairs in the throat of the 5-lobed corolla; borne in terminal panicles or singly in the axils of leaves. Found throughout the south in pastures, fields, roadsides, about homesites and waste places.
TOXICITY
This toxic plant contains "perilla ketone" that is known to produce pulmonary edema and pleural effusion in a variety of animals. Toxic cases are seen sporadically, usually in the late summer or fall after grazing of the plant, most often in cattle and horses.
SYMPTOMS
Affected animals exhibit respiratory distress. There is difficult breathing especially when exhaling. Grunting is often seen when exhaling. There may be a nasal discharge and an elevated temperature; friction sounds can be heard over the chest wall.
Post mortem examination reveals pulmonary emphysema and edema. The perilla mint seeds are often found in the rumen of the cow.
TREATMENT
Once symptoms of severe pulmonary edema and emphysema are observed, treatment is usually ineffective. Injections of antihistamines, steroids and antibiotics are indicated. Cattle should be handled quietly to prevent further respiratory complication and subsequent death.
