104 



showing that the action of the poison is both insidious and cumulative. 

 Little is known of the actively poisonous principle, but it is evidently one 

 or more of the alkaloids which have been isolated from various species 

 of ragwort. 



Symptoms: In regard to the cases of poisoning in Canada it was 

 found that the disease was progressive, and to the careful observer certain 

 premonitory symptoms were visible sometimes months before more 

 characteristic manifestations appeared. In one case reported upon by 

 Pethick, by actual experiment which lasted eighteen months and twenty- 

 one days, death occurred only forty-four days after the first visible 

 symptoms. ''In this case," he says, ''as indeed in nearly all others, we 

 noticed a peculiar bleached appearance of the hair, which seemed to have 

 lost its lustre, a desire to be alone, irritation of temper or nervousness, 

 occasional chills, although in a moderately warm stable. This animal 

 would stand and shiver while the healthy members of the herd appeared 

 comfortable. The bowels are irregular, the pulse at this stage is fast 

 although quite strong, temperature slightly above normal." Later and 

 more characteristic symptoms are: visible mucous membrane pale, 

 eyes amaurotic, slight diarrhoea, emaciation, followed by great weakness, 

 staggering gait, inability to rise, and finally death. 



Remedy and Means of Control: Although strychnine and iron 

 may be used in incipient cases with beneficial results, it was shown by 

 these experiments that measures of this kind are of little real value. The 

 best means of controlling the disease is through the eradication of the weed, 

 and for this purpose (Report Veterinary Director-General, 1911), "The 

 farmers in the counties of Pictou and Antigonish, as also those portions 

 of Prince Edward Island where the weed and the disease existed, were 

 strongly advised to make use of sheep as an economical and profitable 

 means of eradicating this troublesome plant. Numerous farmers followed 

 this advice, but many other methods of eradicating ragwort were also 

 inaugurated, while the practice of removing it from the hay when cut was 

 almost universally adopted. As a consequence, loss from the disease has 

 become almost unknown." 



