The subject of poisonous plants is an important one and is of especial interest to those using the western stock ranges, for it is probable that there is no other single cause producing so many fatalities. In this article only a few of the more important plants are treated in a brief way, for an extended treatise would be necessary if the subject were to be handled adequately. Further information should be sought in the more elaborate publications. Many of the American poisonous plants have been treated in bulletins issued by the United States Department of Agriculture.
Treatment for plant poisoning.—Remedies given by the mouth in most cases fail to give relief to cattle affected by poisonous plants. The material of the poisonous plants in the first stomach is not very largely affected by a remedy given as a drench. If any beneficial result is effected, it must be on the material which has already passed into the fourth stomach, so that to get any real antidotal result the remedy must be given repeatedly in order to meet the alkaloid poisons as they are passing through the fourth stomach. While certain substances like tannic acid and potassium permanganate are the logical antidotes for plant poisons, in practical application they are very disappointing in the treatment of ruminant animals. Reliance must be mainly on prevention and upon such remedies as will increase elimination. A laxative or purgative is always helpful, and for this purpose Epsom salt may be given in pound doses, or linseed oil in doses of 1 or 2 pints. In some few cases special remedies can be given as is indicated below.
It is well to bear in mind that cattle while grazing freely in good pasture are not likely to eat poisonous plants to any extent. If these same plants are gathered and thrown in a pile, the animals, through a kind of pernicious curiosity, may eat them with disastrous results. This has frequently happened when freshly cut branches of cherry, yew, oleander, and other plants have been thrown where dairy cattle could get at them.
OAKS.
The foliage of oaks is a valuable constituent of the forage on many ranges and pastures. It has been shown, however, that when this is eaten without some admixture of other food, cattle frequently sicken and die. Many cases of the poisoning of cattle by acorns have been reported in England and Germany, and there have been some complaints in the United States. Harmful results from eating acorns do not seem likely to occur except as they are eaten in considerable quantities.
Symptoms.—The symptoms of oak poisoning are constipation, mucus and blood in the feces, emaciation, and edema. The symptoms of acorn poisoning are much the same.
Treatment.—Change of pasture or an addition of other food material.
HORSE CHESTNUT—BUCKEYE.
All the species of Æsculus, popularly known as horse chestnut or buckeye, are considered poisonous. The bark, leaves, and fruit are injurious. It is said that if the fruit is boiled or roasted and washed out it becomes harmless and even is a desirable addition to the feed of cattle. The Indians in time of scarcity of food have used the fruit after preparing it in this way. The buckeyes are said to have a specific effect in producing abortion in cattle and goats.