E. L. TAYLOR AND K. M.
SANDERSON
163
disturbance in a second one. A similar result was obtained by Lapage (re-
ported elsewhere in this symposium) who found repeated doses of compara-
tively small amounts of phenothiazine to be markedly toxic for pigs. Manson-
Bahr, in a private communication to us, has reported that no toxic symptoms
were noted in a human patient after a thrice-repeated daily dose of 8 grammes
the anthelmintic effect of which was very satisfactory.†
ADMINISTRATION AND DOSAGE.
One great advantage of this drug is its comparative tastelessness, so that
animals will take it voluntarily, mixed with the food, a point which is of parti-
cular importance in the treatment of the horse and is likely to add consider-
ably to the extent to which phenothiazine will be generally employed. Al-
though the suspicions of a well-fed animal, on being presented with a medicated
feed, may be aroused to such an extent that he will refuse it, a fast of a few
hours ' duration usually overcomes the disinclination and the feed, which
should be made as tempting as possible, is taken without further difficulty.
This method may also be employed in pigs, although Lapage points out
elsewhere in this symposium that by mixing the drug with the pigs' food certain
members of a group, which are more hungry, or less sensitive to the slight taste
of phenothiazine, may get much more than the calculated dose and their com-
panions much less. The method may also be used in the treatment of sheep,
and the occasional medication of dry feed in this way is one of the possibilities
for carrying out periodic dosing that is worthy of serious consideration. The
results of experiment No. 8 suggest that a dose of 2 grammes may be adequate
for this purpose, although 5 grammes is better.
During the early part of our work it was feared that the bulky nature of
phenothiazine, and the large size of the dose that was thought to be necessary
would have a serious reaction on its general usefulness in sheep. In co-opera-
tion with Imperial Chemical Industries, however, two preparations have been
made, a suspension containing about 40 per cent. by weight of phenothiazine,
and a tablet, containing 5 grammes of phenothiazine along with a little exci-
pient and a substance that brings about the rapid disintegration of the mass
when placed in water, these have proved very good indeed.
Every opportunity has been taken to have the two methods of adminis-
tration (in liquid and in tablet form) tried out by various people who have been
using the drug in sheep, and opinion on their relative merits has been almost
equally divided. The tablets are given by means of a rubber-ended balling
gun and in our experience are to be preferred over the administration of a
liquid where the dose to be administered is not a large one. On one occasion
we were able to give a dose of 10 grammes (two tablets) to each of 120 ambs in
only 45 minutes, without undue haste. Taking into consideration the greater
safety of the tablet over the liquid method we are of the opinion that the tablet
method is the better, although on account of the necessity of using a special
balling gun the liquid may prove the more generally useful preparation.
Cattle can easily be treated by the administration of a liquid or of a
draught made from tablets allowed to disintegrate in water or gruel.
† Manson-Bahr gave single doses of 30-40 grammes without ill effect except in one
instance, when the 41 gramme dose produced sickness.
G