402 ABSTRACTS
Abortions in the vaccinated lot ranged from zero to 7.1 per cent in the different
farms with an average of 3.3 per cent for all the farms taken together. Corresponding
figures for the unvaccinated controls were 13 to 30 per cent in the different farms with an
average of 25.1 per cent for the whole lot. These figures refer to actual abortions only
and do not include normal deliveries with retention of after-births, premature calving,
still-births, etc. The percentage of such uncertain calvings was twice as much in the
control group as in the vaccinated group. The conclusion has, therefore, been reached
that future vaccination against infectious abortion in cattle with employment of living
culture ought to be applied to the calves.
The experiment was not controlled by bacteriological examination.
[V. R. R.]
(1) The value of phenothiazine in the treatment of oesophagostomiasis
in sheep. F. H. S. ROBERTS (1939). Aust. Vet. J. 15, 237.
(2) The anthelmintic efficiency of phenothiazine. H. M. GORDON (1939),
Aust. Vet. J. 15, 245.
I N these two papers are given results of trials conducted at two different stations
and directed principally against Oesophagostomum columbianum, the nodule worm
of sheep, with phenothiazine (thiodiphenylamine), a drug that came into prominence
recently on account of its extreme toxicity for certain insects and its apparent harmless¬
ness for man and animals.
Roberts employed ' thiox', a commercial preparation containing 93 per cent
phenothiazine and 5 per cent betanaphthol, marketed by the Imperial Chemical Indus-
tries of Australia and New Zealand, and used 92 sheep and lambs for his experiments.
With a view to ensure passage of the drug straight into the abomasum, reflex closure
of the oesophageal groove was attempted by preliminary treatment with 2 ml. of 10
per cent copper sulphate. At a dose rate of 0.15 gm. per lb. body-weight administered
in a watery suspension, following copper sulphate stimulation and after a starvation
period of 24 hours, phenothiazine gave fairly good results as judged by the percentage
of worms passed after treatment and those collected post-mortem. Nearly 72 per cent of
28 sheep thus treated passed from 60 to 100 per cent of the worms. With dose rates of
0.4 gm. and 0.5 gm. per lb. body-weight, without copper sulphate stimulation, the
results, though somewhat less satisfactory in lambs, were efficient in grown sheep, only
one of 19 six-tooth wethers thus treated giving a percentage efficiency of less than 75.
The poor response of some sheep to treatment appeared to be associated with such
factors as tendency to constipation and quantities, of ingesta present in the intestines
of unstarved animals which delay the passage of the drug to the large bowel, thus per-
mitting a high percentage of it to be broken down and absorbed.
Phenothiazine was also found very efficient against H. contortus but had no anthel-
mintic value against Trichuris spp.
Gordon used both the commercial preparation and the pure drug and found them
equally efficient. In his series of experiments conducted on 42 sheep, phenothiazine in
doses of 0.5 to 0.6 gm. per kg. body-weight, proved an efficient anthelmintic for
the treatment of oesophagostomiasis, removing from 60 to 100 per cent of worms in nearly
78 per cent of sheep treated irrespective of whether it was swallowed into the abomasum
or into the rumen. The results obtained suggested that the dose might possibly be
reduced, without lowering its anthelmintic efficiency, provided a preliminary dose of copper
sulphate is used. In these investigations a 60 per cent removal of worms was accepted
as a satisfactory treatment.
In a special trial specifically designed to test the anthelmintic efficiency of this drug
against H. contortus, doses of 0.3 to 0.75 gm. per kg. body-weight, repeated on three
successive days, in capsules showed 100 per cent efficiency in all of 7 sheep treated.
In a later trial against Trichostrongylus spp., a single dose of 0.6 gm. per kg.
body-weight, administered in capsules, reduced egg counts by 90 per cent or more.
The urine of treated animals took on a reddish colour on exposure to air, which is
explained as due to the excretion by the kidneys of thionol, a phenothiazine derivative.