Jan. 20, 1923 
Carbon Tetrachlorid as an Anthelmintic 
181 
Sheep No. 4c.—Weight 80 pounds (about 36 kilos); given 8 cc. in one 
No. 11 capsule; passed 59 hookworms in 2 days and none the next 2 days; 
post mortem, 2 CEsophagostomum columbianum, 1 Moniezia sp., and a 
few Gongylonema scutatum. 
Sheep No. 5c.—Weight 68 pounds (about 31 kilos); given 4 cc. in one 
No. 10 capsule; passed 40 hookworms in 1 day and none the next 3 
days; post mortem, 14 Haemonchus contortus , 1 CEsophagostomum co¬ 
lumbianum , 95 small trichostrongyles, and a few Gongylonema scutatum . 
Preliminary fecal examinations indicated that all these sheep were 
infested with stomach worms, and it is possible that the worms present 
in 2 of the sheep were destroyed by the carbon tetrachlorid and digested, 
leaving no evidence in the form of recognizable fragments in the manure. 
However, it appears from this experiment that a dose of 4 cc. of carbon 
tetrachlorid is too small to remove all stomach worms present and that 
it is necessary to use at least 8 cc., and possibly more, to remove all 
these worms. 
In our first series of 4 sheep no hookworms were present. In the 
second series the 2 animals treated with 15 and 30 cc. in castor oil passed 
5 and 2 hookworms, respectively, and had none post mortem. The 
control animal had 18 hookworms. In the third series the 2 infested 
animals treated with 4 and 8 cc. in capsules passed 40 and 59 hook¬ 
worms, respectively, and had none post mortem. In view of the efficacy 
displayed by this drug against other hookworms and against blood¬ 
sucking strongyles in general, it seems probable that the same complete 
efficacy would have been shown if large numbers of hookworms had been 
present. This is very promising, especially in view of the removal of 
all hookworms present by a dose as small as 4 cc. In the experiments 
reported by Hall and Foster (79) the copper-sulphate treatment failed 
to remove any hookworms, and the same was true of chloroform. Gaso¬ 
line removed only 5 per cent of these worms. Chenopodium removed 
66 per cent and petroleum benzine 73 per cent. The chenopodium, how¬ 
ever, had an indicated efficacy of only 4 per cent against stomach worms 
and the petroleum benzine an indicated efficacy of 88 per cent in com¬ 
parison with the ascertained 100 per cent efficacy of carbon tetrachlorid 
against stomach worms in doses of 12 cc., and perhaps 8 cc., and against 
hookworms in doses as small as 4 cc. 
In the first series of 4 sheep the carbon tetrachlorid in doses of 12 to 
48 cc. removed 30 per cent of the nodular worms and 30 per cent of the 
whipworms. In the second series of 2 sheep the carbon tetrachlorid in 
doses of 15 and 30 cc. removed 90 per cent of the 189 whipworms present 
from one animal and all of the 12 whipworms present from the other. 
This looks promising. Whipworms, as we have already noted, are very 
difficult to remove with one treatment, but if sheep will tolerate large 
doses of carbon tetrachlorid, this may furnish us with a satisfactory 
treatment for the removal of these worms. In the second series of 2 
sheep the treatment removed only 3 per cent of the 192 nodular worms 
present in the case of the sheep from which it removed over 90 per cent 
of the whipworms. The drug removed all of the 12 nodular worms 
present in the other animal. In the third series the drug failed to 
remove any of the 3 nodular worms present when given in doses of 4 
and 8 cc. 
In our first series of 4 sheep we found that the carbon tetrachlorid 
removed 82 per cent of the 801 small trichostrongyles belonging to the 
