veh. i8, i9i8 Efficacy of Some Anthelmintics 399 



EXPERIMENTS WITH SIMPLE PURGATIVES 

 CALOMEly 



For worms in dogs. — Calomel in, fairly large single doses followed 

 by castor oil proved inefficacious as a remedy for ascarids in dogs. 

 Four infested pups weighing 3.6 to 4.5 kgm. were fasted from noon 

 of the day before treatment, given 4 to 5 gm. of calomel, and on the 

 day following treatment given 1 5 mils (milliliters) of castor oil. Three 

 of the dogs passed no worms after treatment ; one passed a single as- 

 carid (Belascaris marginata). Two of the dogs which passed no worms 

 when examined post-mortem showed 10 and 8 B. marginata, respec- 

 tively. The treatment was so evidently inefficacious that the other 

 two dogs were not sacrificed for post-mortem examination. The results 

 of this experiment do not accord with the claims occasionally made 

 as to the anthelmintic value of simple purgatives and cathartics. 



CASTOR oily 



For WORMS in dogs. — Although the efficacy of castor oil as an an- 

 thelmintic was not tested as a separate experiment, in several experi- 

 ments it was given as a preliminary purge. The feces passed follow- 

 ing its use were examined, and the worms passed compared with the 

 number found post-mortem. In these experiments only 24 hours 

 were allowed between the administration of the oil and the subsequent 

 anthelmintic. It is therefore possible that the oil alone might have 

 shown greater efficacy if the feces were collected for a longer time. 

 However, in our experience the greater number of worms are passed 

 within 24 hours after the administration of an anthelmintic; and in the 

 case of a drug like castor oil, which usually acts within a few hours after 

 its administration, it is not likely that the conclusions of the writers are 

 much in error. 



In II experiments in which castor oil was used as a preliminary purge 

 on 50 dogs it removed 27 B. marginata out of a total of 351. Its effect 

 on hookworms (Ancylostoma caninum) and whipworms (Trichuris de- 

 pressiuscula) was practically nil. It was ineffective more frequently than 

 it was effective, and in no case did it remove all the ascarids from a 

 single dog. It has therefore little to recommend it as an anthelmintic. 

 It may, however, have some diagnostic value in veterinary practice to 

 confirm a clinical diagnosis of ascarid infestation in dogs when a micro- 

 scopic examination of the feces is impossible, though it is evident that 

 even for this purpose it would not always be reliable. 



When worms are passed as the result of the increased peristalsis due to 

 a simple purgative, there is always the suspicion that the worms were dead 

 and would have passed out anyway and that the purge merely hastened 

 their removal. 



