Feb. i8. 1918 Efficacy of Some Anthelmintics 433 



The foregoing experiments with chenopodium and chloroform, in 

 comparison with other standard anthelmintics used for the removal of 

 worms from dogs, indicate that oil of chenopodium is the best anthel- 

 mintic of those tried for use against ascarids {Belascaris marginata and 

 Toxascaris limhata). In the 6 experiments, involving the use of 34 

 experiment animals, it removed 194 out of 200 ascarids, an efficacy of 

 97 per cent. It is at the same time probably a little more efficacious 

 against whipworms (Trichuris depressiuscula) than any other anthel- 

 mintic tested. In the entire six experiments its average percentage of 

 efficacy was only 12, a figure which illustrates the difficulty experienced 

 in dislodging this parasite. Moreover, it is probable that the chloroform 

 used in three of the experiments may be responsible for the removal 

 of some of these worms, since both chloroform and chenopodium were 

 found to have a limited efficacy for whipworms when given separately. 



As regards hookworms (Ancylostoma caninum), the experiments of the 

 writers with chenopodium do not show as high an average efficacy 

 for this drug as they had been led to expect, considering the warm 

 indorsement chenopodium has frequently received as an anthelmintic 

 for the hookworm of man. Undoubtedly chenopodium as well as thymol 

 would have to be given in repeated doses and the treatment renewed 

 in order to secure a high percentage of efficacy. The writers have found 

 chloroform much more efficacious than chenopodium for hookworms in 

 dogs, and, when given at the rate of 0.2 mil per kilo, is apparently free 

 from danger. 



For worms in hogs. — A series of experiments to test oil of chenopo- 

 dium as an anthelmintic for ascarids in swine were carried out by the 

 junior writer and seemed to indicate the great value of this drug when 

 given to hogs individually after a period of starvation. In these experi- 

 ments the hogs were not killed, the effect of the anthelmintic being 

 judged by the presence or absence of ascarid eggs in the feces passed 

 subsequent to treatment. 



In the first experiment with chenopodium an effort was made to 

 determine the minimum effective dose necessary to free a hog from 

 ascarids. In this case the dose of oil was combined with 3.7 mils of 

 areca nut and mixed with the feed, after starving the pigs. Each pig 

 was fed separately, thus assuring full dosage to each animal. Two pigs, 

 weighing 11.32 and 14.06 kgm., respectively, were given 0.2 mil of 

 chenopodium, while a third pig weighing 37.9 kgm. received 0.4 mil. 

 This latter pig was apparently free from ascarids after a single dose, 

 while the two other pigs each received three additional doses of 0.27 mil, 

 0.36 mil, and 0.54 mil before their feces were negative for ascarid eggs. 



It is evident from the above that, even when given mixed with feed, 

 a method later shown to be unsuitable, a relatively small dose of oil of 

 chenopodium may prove efficacious. It should be stated in comment 

 that at the time these experiments were conducted there was little 



