Journal of Agricultural Research 
Vol. XXIII, No. 3 
168 
enough may be absorbed to cause death. The dose which was tolerated, 
at the rate of 5 cc. per kilo, would give a safety factor of almost 17 on 
the basis of the therapeutic dose for dogs—namely, 0.3 cc. per kilo. 
This is a distinctly lower safety factor than that for this drug in the case 
of dogs, but it is nevertheless a high safety factor for drugs in general. 
A very casual determination by water displacement of the gastric capac¬ 
ity of a rabbit weighing 7 pounds (a little over 3 kilos) showed it to be 
about 200 cc. Ten cc. per kilo being considered as the minimum lethal 
dose, the minimum lethal dose for this rabbit would be over 60 cc., or 
more than 30 per cent of the gastric capacity. A rabbit weighing 1.97 
kilos had a gastric capacity of 125 cc. of which the minimum lethal dose 
would equal almost 16 per cent, and a rabbit weighing 1.65 kilos had a 
gastric capacity of 120 cc. of which the minimum lethal dose would equal 
almost 14 per cent. 
TESTS ON DOGS 
In a paper by Hall ( 13 ), already referred to, tests were reported of the 
use of carbon tetrachlorid on 30 dogs. These tests showed that when 
administered in hard capsules in doses of 0.3 cc. per kilo of live weight—a 
dose of 3 cc. for a dog of average weight, 10 kilos (22 pounds)—this drug 
would remove all the hookworms present. Apparently, no purgation is 
necessary and the drug itself is not constipating. Equally good results 
were obtained by the use of a solution containing 10 grains of thymol to 
1 cc. of carbon tetrachlorid, the solution being given at the same dose 
rate as the carbon tetrachlorid alone, 0.3 cc. per kilo. One hundred per 
cent efficacy was also obtained by the use of a solution containing 3 parts 
by volume of carbon tetrachlorid and 1 part of oil of chenopodium, the 
solution being given at the same dose rate as the carbon tetrachlorid 
alone. The removal of all hookworms present by carbon tetrachlorid, 
or mixtures containing this drug, from a series of infested dogs is a result 
which it has been impossible to obtain in scores of experiments with 
chenopodium, chloroform, thymol, and other drugs. It apparently 
solves the problem of treatment for hookworm disease in dogs. It has 
been favorably reported on by Smyth (29), and we have had favorable 
reports in correspondence from and in conversation with a number of 
veterinarians in various parts of the United States. Brumley in 1922 
stated: “I wish to report that carbon tetrachlorid has given us excellent 
results in removing hookworms from dogs. Its use has demonstrated 
its superiority over any of the other anthelmintics used to date. ” Dr. 
D. E. Buckingham, of Washington, D. C., tells us that he has given it 
to more than 500 dogs and cats with no bad results, even in the case of 
pups 2 weeks old or kittens 3 weeks old. 
When administered in hard capsules at the dose rate stated above, 
carbon tetrachlorid removed not only all the hookworms, but also all 
the ascarids present. Other experiments at different dose rates indicate 
that this drug is probably not so effective against ascarids as is oil of 
chenopodium, but it appears to be only second to this highly effective 
drug in removing these worms. 
Carbon tetrachlorid is substantially as effective in removing whip¬ 
worms as is any other good anthelmintic. In a general way one may 
say that almost any anthelmintic will remove whipworms if it comes in 
contact with them, but the establishment of such a contact is usually a 
matter of accident. If an anthelmintic enters the cecum after passing 
the ileocecal valve it will probably remove the whipworms with which 
