_Remarks._--As the more general use of clysters is recommended by the
author, especially in acute diseases, he has thought proper to
introduce, in this part of the work, a few remarks on them, with
examples of their different forms. They serve not only to evacuate the
rectum of its contents, but assist to evacuate the intestines, and
serve also to convey nourishment into the system; as in cases of
locked-jaw, and great prostration. They soften the hardened excrement in
the rectum, and cause it to be expelled; besides, by their warm and
relaxing powers, they act as fomentations. A stimulating clyster in
congestion of the brain, or lungs, will relieve those parts by
counter-irritation. An animal that is unable to swallow may be supported
by nourishing clysters; for the lacteals, which open into the inner
cavity of the intestines, absorb, or take up, the nourishment, and
convey it into the thoracic duct, as already described. Some persons
deny the utility of injections. We are satisfied on that point, and are
able to convince any one, beyond a reasonable doubt, that fluids are
absorbed in the rectum, notwithstanding the opinion of some men to the
contrary.
In administering clysters, it ought always to be observed that the
fluids should be neither too hot nor too cold: they should be about the
temperature of the blood. The common sixteen-ounce metal syringe, with a
wooden pipe about six inches in length, and gradually tapering from base
to point, is to be preferred. It is, after being oiled, much more easily
introduced into the fundament than one that is considerably smaller;
and, having a blunt point, there is no danger of hurting the animal, or
wounding the rectum.
The following injections are suitable for all kinds of animals. The
quantity, however, should be regulated according to the size of the
patient. Thus a quart will suffice for a sheep or pig, while three or
four quarts are generally necessary in the case of horses and cattle. If
clysters are intended to have a nutritive effect, they must be
introduced in the most gentle manner, and not more than one pint should
be given at any one time, for fear of exciting the expulsive action of
the rectum. In constriction and intussusception of the intestines, and
when relaxing clysters are indicated, they should not be too long
persevered in, for falling of the rectum has been known, in many
instances, to arise from repeated injections. Efforts should be made to
relax the whole animal by warmth and moisture externally, and in the
use of antispasmodic teas, rather than to place too much dependence on
clysters.