Oct. 1, 1924 
Critical Tests of Miscellaneous Anthelmintics 
327 
of the horse such small worms as Hab- 
ronema may be macerated beyond 
recognition. 
TESTS OF NOVARSENOBENZOL ON 
STRONGYLES IN VERMINOUS 
ANEURISMS OF THE HORSE 
PROTOCOL 
Horse No. 223, an old animal weigh¬ 
ing 710 pounds, was given daily intra¬ 
venous injections of novarsenobenzol 
(Billon) in amounts of 3.6 gm. dissolved 
in 40 cc. of sterile distilled water, 
slowly injected into the jugular vein. 
The animal showed no pronounced 
symptoms from the injections until the 
fourth day, when it became uneasy 
5 minutes after the injection, staggered 
and almost fell, breathed hard, and 
passed watery feces and some gas. 
It tried to eat but stopped to look at its 
flanks and the skin quivered over the 
flank region. The respiration was 
68 and shallow. Apparently the drug 
caused cramps and extreme peristalsis. 
The animal was killed 3 days after this 
last dose, and an examination was 
made for worms in an aneurism of the 
.anterior mesenteric artery which was 
about 7 or 8 inches long and involved 
the nearby arterial branches. Em¬ 
bedded in the thrombus and in the 
thickened arterial walls were 14 live 
specimens of Strongylus vulgaris in a 
late larval stage, all ensheathed in a 
somewhat loose cuticle. One addi¬ 
tional specimen could not be definitely 
identified since it appeared to be either 
a dead and partially disintegrated 
strongyle or a shed cuticle filled with 
some dark material. 
In a previous paper Hall and Shil- 
linger (20) have reported failure to de¬ 
stroy these worms with intravenous in¬ 
jections of tartar emetic and of carbon 
tetrachloride. So far no treatment is 
known for destroying these worms; 
and, on the available evidence, no 
promising results can be expected from 
tartar emetic, carbon tetrachloride, or 
novarsenobenzol. 
GENERAL SUMMARY AND 
DISCUSSION 
EXPERIMENTS ON DOGS 
Ascarids. —A mixture of carbon 
tetrachloride, 3 parts by volume, and 
chenopodium, 1 part by volume, given at 
a dose rate of 0.3 cc. per kilogram with 
one-eighth to one-half grain arecoline 
hydrobromide according to the size of 
the dog, shows a rather high efficacy, 
90 per cent, in removing ascarids from 
dogs, but this efficacy is slightly less 
than that usually obtained with cheno¬ 
podium or carbon tetrachloride given 
without arecoline hydrobromide. The 
number of infested animals and of 
worms present in the experiment was 
not sufficient to warrant the conclusion 
that the slight loss in indicated efficacy 
would be sustained in a larger series of 
cases. 
The simultaneous administration of 
magnesium sulphate with a therapeutic 
dose of chenopodium at the rate of 
0.1 cc. per kilogram gives an indicated 
efficacy of 94 per cent, showing that the 
salts do not materially diminish the 
efficacy of the chenopodium. 
Novarsenobenzol in repeated doses 
by mouth was entirely ineffective 
against ascarids. 
Hookworms. —The mixture of car¬ 
bon tetrachloride, chenopodium and 
arecoline hydrobromide removed all 
the hookworms from only 78 per cent 
of the dogs in these experiments, re¬ 
moving 46 per cent of the total number 
of hookworms present. This is a de¬ 
cided loss of efficacy compared to the 
100 per cent efficacy of carbon tetra¬ 
chloride alone or of the mixture of carbon 
tetrachloride and chenopodium, con¬ 
traindicating the simultaneous use of 
arecoline hydrobromide with these 
drugs for this purpose. 
The therapeutic dose of chenopodium 
for ascarids when given with salts re¬ 
moved the one hookworm present; no 
positive conclusion can safely be drawn 
from this test. 
Benzyl-phenol in single doses of 20 
and 30 grains and in doses of 20 grains 
one day and 30 grains the following day 
removed only 7 per cent of the hook¬ 
worms from the experiment animals. 
While chemicals having a free phenolic- 
hydroxyl group have a certain efficacy 
against hookworms, as shown here, the 
efficacy of such compounds, including 
thymol, is low against hookworms in 
dogs. 
Ethylene dichloride at a dose rate of 
0.3 to 0.5 cc. per kilogram of weight of 
animal removed 0 to 9 per cent of the 
hookworms in single doses and in two 
doses at the rate of 0.5 cc. per kilogram 
removed 67 per cent from infested dogs. 
This efficacy is lower than that ob¬ 
tained by Hall and Foster (18) and by 
Hall (15) for chloroform, their average 
for single doses being 52 per cent; and 
is distinctly lower than the 100 per 
cent efficacy of carbon tetrachloride in 
single doses at the rate of 0.3 per kilo¬ 
gram. This loss of efficacy appears to 
be associated with the diminished 
