Poisoning 491 
turned to pasture, or when there is any violent or sudden 
change of food, they should be well fed and watered 
before the change is made. They should not be turned 
on pastures until the grasses are well started, so that 
they can get sufficient food without eating weeds or 
other plants that usually start early and that may be 
injurious. Animals that are in poor condition are more 
liable to die from eating poisonous weeds than those in 
good flesh. 
Among the common plants that are poisonous under 
certain conditions, are cockle-burs (Xanthium). These 
are poisonous when they are first starting in the spring, 
and have but two leaves. Severe losses among both 
hogs and cattle are caused throughout the middle west 
from eating this weed. The leaves of the wild cherry 
{Prunus serotina), especially when wilted, are also 
poisonous.. Tansy is poisonous, although animals will 
seldom eat it unless starved to it; so are the roots 
and young sprouts of the wild parsnip, or cow-bane, 
jimpson weed, yarrow, laurel, buckeye, nightshade, lark- 
spur, sumac, poison ivy, and black nightshade; also, 
some fungi commonly known as toadstools. These 
fungi include the “fly amanita” and “death-eup.” 
The symptoms of poisoning usually begin within 
twenty-four to forty-eight hours after the animals are 
turned on the pasture where the poisonous plants grow. 
The symptoms vary with the condition of the animal 
‘and the amount of the poisonous plants eaten. In 
general, the symptoms may be divided into two groups: 
(1) The first are marked by an irritation of the stomach 
and bowels. These are discharge of saliva in pigs, 
