i8o 
Journal of Agricultural Research 
Vol. XXIII, No. 3 
TESTS ON SHEEP 
The results of our tests of carbon tetrachlorid on sheep have been very 
satisfactory from the standpoint of efficacy. In one series, 4 lambs, 
which were found on fecal examination to have a moderate infestation 
with stomach worms, were given, respectively, 12, 18, 24, and 48 cc. of 
carbon tetrachlorid, the drug being mixed in each case with 2 ounces 
of castor oil and administered by means of a dose syringe. We recovered 
9 stomach worms (Haemonchus contortus) from the manure of one, 8 
from another, and 2 from a third. On post-mortem examination all the 
animals were found to be entirely free from stomach worms. This 100 
per cent efficacy is superior to the results obtained from the use of copper- 
sulphate solution by Hall and Foster (19) and is additional evidence 
showing the particular efficacy of this drug against the bloodsucking 
worms. As the fecal examinations indicated that all of these animals 
were moderately infested with stomach worms, the failure to obtain these 
worms from the manure of one animal and the collection of such small 
numbers in the case of the other three are evidently due to the digestion 
of the worms in the stomach, as in the case of Habronema in the horse. 
The stomach worms lie among the laminae of the abomasum and this, 
doubtless, further insures digestion by holding them until they are 
digested, except in the case of the worms near the pylorus. That this is 
true is evident from the findings of Hall and Foster. Following the 
administration of a 1 per cent solution of copper sulphate to 3 sheep, they 
recovered, respectively, 120, 240, and 314 stomach worms from the 
manure. Two other sheep from the same flock were given copper 
sulphate in capsules; each passed 41 stomach worms, and had, respec¬ 
tively, over 4,000 and over 6,000 of these worms post mortem. It seems 
quite reasonable to assume that there was probably an average of 5,000 
worms originally present in all 5 animals and that less than 10 per cent 
of the worms killed by the copper-sulphate solution were collected from 
the manure. 
A second experiment carried on by us indicates much the same results. 
Of 3 lambs, all heavily infested as shown by fecal examination, 1 was 
held as a control and the other 2 were given, respectively, 15 and 30 cc. 
of carbon tetrachlorid in 2 ounces of castor oil. Three stomach worms 
were collected from the manure of one animal and no worms of this sort 
were present post mortem in either animal. The control animal had 612 
stomach worms post mortem. We must conclude that the carbon 
tetrachlorid was 100 per cent effective in removing the stomach worms 
from 6 sheep and that the failure to obtain worms from the manure in 
two of these cases is due to the digestion of the worms in the stomach, 
which also accounts for the small number recovered in the other cases. 
It may be further said that stomach worms collected from the manure 
after treatment are usually represented only by small fragments, fre¬ 
quently the portion found showing the characteristic vulva region in the 
female. Entire worms are rarely found. It may also be mentioned that 
apparently carbon tetrachlorid itself has a destructive action on hook¬ 
worms and may have a similar action on other worms. 
A third series of tests on sheep was conducted as follows : 
Sheep No. 3316.—Weight 80 pounds (about 36 kilos); given 12 cc. in 
one No. 10 and one No. 12 capsule; passed no worms in 4 days; post 
mortem, 36 small trichostrongyles and 6 Moniezia sp. 
