420 Journal of Agricultural Research voi.xii.no. 7 



pean or Asiatic origin, the present price of santonin is almost prohibitive 

 in veterinary medicine, and its place is being taken by the native and, in 

 the writers' experience, more effective drug chenopodium. Santonin is 

 usually combined with or followed by a purgative to promote elimina- 

 tion of the parasite. For this purpose calomel or areca nut is much 

 used. 



Santonin and calomel for worms in dogs. — The dose of santonin 

 for dogs recommended by Winslow {19 13) is from i to 3 grains (65 to 

 195 mgm.). Taking 130 mgm. as the dose for an average dog weighing 

 iokgm.,the writers gave seven dogs, ranging in weight from 3.8 to 9.5 

 kgm., doses graded from 32 to 130 mgm., accompanied by the same 

 amount of calomel. The treatment was preceded by the administration 

 of castor oil, 29.57 mils to dogs weighing 4.5 to 9.5 kgm., and 7.39 mils 

 to pups under 4.5 kgm. Food was withheld the previous day. Seven 

 ascarids (Belascaris marginata) were passed following the administration 

 of castor oil and 13 B. marginata and two whipworms (Trichuris depres- 

 siuscula) after santonin and calomel. At the post-mortem examination 

 it was found that about one-fourth of the ascarids remaining after the 

 action of the castor oil later had been removed by santonin and calomel. 

 The treatment was very inefficacious for whipworms, removing 2 out of 

 72, and entirely inefficacious for Dipylidium caninum and Taenia. 



It would appear from the foregoing that santonin and calomel, the 

 remedy usually prescribed for ascarids, is not very efficacious for dogs 

 in single doses. 



As the efficacy of the santonin as shown by the above experiment 

 was considerably less than had been expected, considering the well- 

 established reputation that santonin has as an ascaricide, a second experi- 

 ment was undertaken to determine the efficacy of santonin and calomel 

 in repeated doses. In this experiment four dogs, weighing from 1.8 to 



9 kilos, were given graded doses of equal quantities of santonin and calo- 

 mel, the dose varying from 32 to 130 mgm., according to weight. The 

 first dose was given after a preliminary fast, and the second dose was given 

 two days after the first, food being withheld the evening before the 

 second treatment also, the same dose being given at each treatment. 

 The first treatment was preceded by castor oil, which failed to eliminate 

 any worms. One of the dogs passed no ascarids and had none post- 

 mortem, so that it was evidently not infested and must be left out of 

 consideration. From the three remaining dogs it eliminated 7 out of 



10 ascarids, a distinct gain in efficacy compared with the previous 

 experiment, in which a single dose was given. In this case the drug 

 also showed a fair degree of efficacy against whipworms {Trichuris 

 depressiuscula), parasites which in the writers' experience are difficult to 

 remove with any degree of certainty with any of the anthelmintics tested. 

 The drug was entirely ineffective against hookworms and Dipylidium 

 caninum. 



