LARKSPUR POISONING OF LIVE STOCK. 7 



Eighth. By avoiding the areas where larkspur abounds during the months of 

 April, May, and June the loss can be reduced to the minimum. 



Ninth, In potassium permanganate and atropin sulphate, respectively, we 

 have a chemical and physiological antidote of real practical value. Stimulants 

 are indicated. Tapping should be done with trocar and cannula high up on the 

 left side, after first making slight incision on the skin with a knife. In case of 

 extreme distention this operation should not be delayed. The value of bleeding 

 is questionable. All measures which tend to depress the animal, such as 

 forcible exercise, tobacco, aconite, etc., are positively harmful. If on sloping 

 ground, the head should be turned up the hill. 



Crawford, 1907, quotes preceding authors in regard to the effect 

 of larkspur upon stock, but adds nothing to what has been written 

 before. Pammel, 1910, page 44, states that " cattle and sheep are 

 most susceptible, although horses frequently suffer." 



Preceding the publication of the present general report on the 

 larkspur investigation, there was issued in 1913 Farmers' Bulletin 

 531, entitled "Larkspur or Poison Weed," which gave some of the 

 practical results of the work. In 1915 Hall and Yates recapitulate 

 the results of this bulletin, applying them to the larkspurs of 

 California. 



It will be seen from the foregoing that up to the time when the 

 detailed experiments of larkspur poisoning were undertaken by the 

 Bureau of Plant Industry, a very definite body of evidence had been 

 accumulated indicating that American larkspurs were poisonous to 

 domestic animals, especially cattle and sheep, causing heavy annual 

 losses in the mountain ranges. There was a fair amount of agree- 

 ment in the descriptions of the symptoms of poisoning. The reme- 

 dial measures recommended were very largely those worked out by 

 Wilcox, and by Chestnut and Wilcox in their Montana work. There 

 were, however, several questions with regard to the poisoning which 

 for practical purposes had to be decided. In the published observa- 

 tions and in the statements made by stockmen, the reports were 

 somewhat contradictory with regard to which part of the plant is 

 most poisonous, although there was a general agreement that the 

 principal losses occur in the spring. It seemed necessary to deter- 

 mine at what time of the year and under what conditions these plants 

 are poisonous, to determine whether the tall larkspurs and the low 

 larkspurs are equally poisonous, to describe in somewhat greater 

 detail the symptoms of poisoning and pathological results, and to ' 

 make further and more detailed experiments upon the possibilities 

 of using remedial measures to lessen the losses. There were also open 

 questions concerning the best method of handling stock so as to pre- 

 vent poisoning. 



It may be noted that practically all accounts of larkspur poisoning 

 of stock in the United States relate to the mountainous regions of 

 tlie West. As will be seen later in this paper, there is no reason to 



