Apr. is, 1921 
Carbon Tetrachlorid for the Removal of Worms 
171 
Gaiger (6 ) gave thymol to 5 dogs in doses of 30 gr., repeated at i-hour 
intervals for a total of 3 doses; the feces were not examined for worms 
passed, but the dogs were examined post mortem several days later and 
hookworms were found in 3 dogs. He then increased the dose to 40 gr. 
and gave this to 4 dogs, all of which had hookworms present post mortem. 
SUMMARY 
From the foregoing, the relative efficacy of carbon tetrachlorid and 
the other drugs commonly used to remove hookworms (chloroform, 
chenopodium, chloroform and chenopodium, and thymol) appear to be 
about as follows: 
Carbon tetrachlorid in less than the ascertained effective dosage (0.3 
m. p. k.) or improperly administered (without capsules) removed 40 
hookworms and left 55, an efficacy of only 42 per cent; but in the effective 
dosage of 0.3 m. p. k. in capsules it removed all the hookworms from 9 
dogs and, judging from the fecal examinations, apparently removed all 
the hookworms from 5 other dogs, an efficacy of 100 per cent. A solution 
of thymol in carbon tetrachlorid in capsules was likewise 100 per cent 
effective against hookworms in the 2 infested dogs to which it was given. 
A solution of chenopodium in carbon tetrachlorid in capsules was like¬ 
wise 100 per cent effective against hookworms in the one infested dog to 
which it was given. 
On the other hand, chloroform in doses of 0.1 to 2 m. p. k. in castor oil 
was only 54 per cent effective against hookworms; in single or repeated 
doses in soft capsules it was entirely ineffective. 
Chenopodium and its constituents in single or repeated doses have an 
average efficacy of 20 per cent against hookworms; in the dose com¬ 
monly employed for removing hookworms from man, three 10-minim 
doses at 1-hour intervals, it is only 30 per cent effective, and its maximum 
efficacy in any series of dogs used is only 74 per cent. 
Chloroform and chenopodium for all cases reported shows an average 
efficacy of 69 per cent, the maximum efficacy for a series being 89 per 
cent in cases where dogs were given three 5- to 10-minim doses in soft 
capsules at i-hour intervals, each dose accompanied by y 2 ounce of castor 
oil and followed a half hour later by 4 mils of chloroform in % ounce of 
castor oil, this dose of chloroform being in excess of 0.3 m. p. k. for the 
average dog (a 10-kgm. dog). 
Thymol shows an efficacy of 15 per cent and according to Gaiger’s 
record left hookworms in 7 of 9 dogs treated, with no evidence as to 
infestation on the part of the other 2 dogs. 
Nothing heretofore reported for experimental tests of anthelmintics on 
dogs shows the 100 per cent efficacy for a series of tests against hook¬ 
worms that carbon tetrachlorid does. The best results heretofore have 
been obtained by repeated doses of chenopodium followed by chloroform. 
