158 
Journal of Agricultural Research 
Vol. XXX, No. 2 
experiment discussed here was con¬ 
ducted from February 28 to April 29, a 
period during which short-lived worms 
might be expected to pass out. The 
writers reserve judgment as to the fact 
in this case. Apparently little is 
known as to the length of life of whip¬ 
worms. In anthelmintic experiments 
for the past 10 years the writers have 
not observed what they regard as the 
spontaneous passage of whipworms, but 
as they have rarely carried on experi¬ 
ments involving the examination of the 
feces of an animal for two months they 
have had little occasion to make ob¬ 
servations on this point. Had they 
carried along some control animals in 
connection with this experiment more 
definite evidence on this point might 
have been secured. A microscopic 
examination of the worms passed dur¬ 
ing the last two weeks of the experi¬ 
ment showed a large percentage of 
males, and as males commonly do not 
live as long as females this finding sug¬ 
gested that these worms were passed 
spontaneously; of the female worms 
some were gravid females containing 
shelled eggs and others old females 
with no shelled eggs, the latter finding 
again suggesting that these worms had 
died of old age and were coming away 
spontaneously. 
The case for hookworms is as follows: 
Dog No. 654 passed 1 hookworm and 
had 20 post-mortem; passed 5 per cent. 
Dog No. 656 passed 2 hookworms and 
had 18 post-mortem; passed 10 per cent. 
Dog No. 658 passed 0 hookworm and 
had 5 post-mortem; passed 0 per cent. 
Dog No. 659 passed 10 hookworms 
and had 242 post-mortem; passed 4 per 
cent. 
These figures, 0, 4, 5, and 10 per cent, 
show the onions to have had little or no 
effect on hookworms. A microscopic 
examination of 3 hookworms passed 
during the last two weeks showed that 2 
of them were males and 1 an old eggless 
female, all of which points to the 
probable spontaneous passage of these 
worms as a result of old age. The dogs 
passed 13 out of 298 whipworms, or 
about 4 per cent. 
The case for ascarids is as follows: 
Dog No. 658 passed 2 ascarids and had 
none post-mortem; dog No. 659 passed 
1 ascarid and had none post-mortem; 
no other dogs were infested with as¬ 
carids. The ascarids present came 
away on the fifth, ninth, and either 
thirty-second or thirty-third day. Ow¬ 
ing to the light infestation here one can 
not draw any positive conclusion. One 
ascarid was an adult female, another a 
young ascarid; no careful examination 
of the third was made. One would be 
inclined to say that if onions were an¬ 
thelmintic the human ascarid should 
have died out among certain races and 
nations where it has persisted, but on 
the other hand it might be urged that 
the human ascarid has become accus¬ 
tomed to and tolerant to onions, where¬ 
as the dog ascarid has had no occasion 
to develop such tolerance and might be 
susceptible to certain anthelmintic ef¬ 
fects. The writers believe, however, 
that if feeding onions for 32 days is 
necessary to remove ascarids, the onion 
has too little anthelmintic value to 
warrant its use in view of the knowledge 
of better anthelmintics which would re¬ 
move ascarids in less than that many 
hours. 
So far as tapeworms are concerned, it 
is sufficient to say that three of the 
dogs had an infestation with Dipy - 
lidium sp. and two with Taenia sp., 
that the dogs continued to pass gravid 
segments during the course of the ex¬ 
periment, and that no tapeworms came 
away as a result of the onion diet. 
SUMMARY AND CONCLUSIONS 
Raw onions in amounts of 2 oz. daily 
to each of 3 dogs for 60 days and to 1 
dog for 37 days showed too little 
anthelmintic value to warrant the use 
of onions as a control measure for 
worms in dogs. The writers are, there¬ 
fore, unable to urge that: An onion' a 
day keeps the worms away. 
The use of onions was evidently of no 
value in removing hookworms or tape¬ 
worms. In spite of the passage of 
numerous whipworms, the nature of 
some of the worms passed and the fac¬ 
tor of mechanical anthelmintic action 
in the case of the dog passing 74 per 
cent of its worms, suggests that the 
worms were passed partly as the result 
of their death from old age and partly 
from the action of mechanical anthel¬ 
mintics. This idea is supported by the 
small percentage of whipworms passed 
by one dog and the failure of another 
dog to pass any. As regards ascarids it 
must be admitted that all the worms 
present (5) were passed during the 
course of the experiment, but the time 
required, up to 32 or 33 days, to remove 
an ascarid from one dog indicates that 
there is too little merit in the onion as 
an anthelmintic for dog ascarids to 
warrant its use. 
