174 
Journal of Agricultural Research 
Vol. XXIII, No. 3 
carbon tetrachlorid in comparatively few cases with apparently good 
results. Subsequently he ( j) has reported that in the treatment of 399 
foxes 95 per cent of the hookworms present were removed. Seven foxes 
were killed by the treatment, probably from inhalation intoxication in 
most cases, due to accidents in administration. Allen (4) has reported 
critical tests on 23 foxes and finds an efficacy of 93 per cent against hook¬ 
worms. A small quantity of castor oil was given by him in connection 
with the administration of the carbon tetrachlorid in capsules. 
Jeffreys (24) has reported the treatment of 69 fox pups, 17 days old 
to 5 weeks old, without evidence of discomfort or ill effects, which indi¬ 
cates the safety of carbon tetrachlorid since drugs in general—and this 
is true of anthelmintics—are much more toxic to young animals than to 
mature animals. Jeffreys found the drug 100 per cent effective against 
hookworm and ascarids. He also reports that it is 100 per cent effective 
in removing intestinal flukes from foxes. According to Jeffreys, the use 
of carbon tetrachlorid “ is worth thousands of dollars to every fox rancher.” 
In another paper, Jeffreys (23) states: “An efficient remedy for the 
removal of hookworms was unknown a year ago, and the blue fox rancher 
was greatly handicapped. Now ... we have an efficient remedy 
in the form of carbon tetrachloride. With this problem of parasites 
practically solved the rancher will have greater success in developing 
the blue fox industry.” 
When capsules break in the mouth and the drug enters the lungs, 
animals can be revived in many cases by artificial respiration. In view 
of the fact that carbon tetrachlorid and its vapors are very heavy, it 
would probably be advisable to hold the animal with its head down to 
assist in mechanically clearing the lungs. 
At the present time effective treatment for the removal of hook¬ 
worms from foxes is a matter of special interest, since fur foxes can not 
be imported into the United States if they are infested with hookworms. 
Previously, the majority of foxes could not be admitted to this country, 
since they are usually infested and no drug then known appeared to be 
safe and effective. Allen ( 4) also found carbon tetrachlorid effective in 
removing ascarids from foxes. We have no reports at present as to its 
value in removing whipworms, but what is true of it in the case of the 
same worms in dogs will probably be true of it in the case of the worms 
in foxes. 
TESTS ON SWINE 
The worm of greatest importance in the case of swine in this country 
is the large roundworm, or ascarid, (Ascaris lumbricoides ). It has added 
interest because it has been generally accepted by parasitologists of late 
years that the ascarid of swine and the ascarid of man are identical; this 
conclusion is reached by Bakker (5) in a recent detailed study. Inasmuch 
as the tests on dogs indicated that carbon tetrachlorid would remove as¬ 
carids from these animals, and in view of the fact that chenopodium, the 
most effective drug known for the removal of ascarids, is of variable com¬ 
position and occasionally gives rise to toxic effects, especially when given 
with inadequate purgation, we carried out some tests of carbon tetra¬ 
chlorid against ascarids in swine as follows: 
A series of 4 pigs, weighing 18 to 24 pounds, were given 6 cc. of carbon 
tetrachlorid in 30 cc. of castor oil by drench and were killed 5 days 
later with the following results: Pig 3381 passed 17 ascarids and had 
