The symptoms of this disease, known as turnsick, sturdy, staggers, water
in the head, etc., are a dull, moping appearance, the sheep separating
from the flock, a wandering and blue appearance of the eye, and
sometimes partial or total blindness; the sheep appears unsteady in its
walk, will sometimes stop suddenly and fall down, at others gallop
across the field, and, after the disease has existed for some time, will
almost constantly move round in a circle--there seems, indeed, to be an
aberration of the intellect of the animal. These symptoms, though rarely
all present in the same subject, are yet sufficiently marked to prevent
any mistake as to the nature of the disease.
On examining the brain of sheep thus affected, what appears to be a
watery bladder, called a hydatid, is found, which may be either small or
of the size of a hen's egg. This hydatid, one of the class of entozooens,
has been termed by naturalists the _hydatis polycephalus cerebralis_, or
many-headed hydatid of the brain; these heads being irregularly
distributed on the surface of the bladder, and on the front part of each
head there is a mouth surrounded by minute sharp hooks within a ring of
sucking disks. These disks serve as the means of attachment, by forming
a vacuum, and bring the mouth in contact with the surface, and thus, by
the aid of the hooks, the parasite is nourished. The coats of the
hydatid are disposed in several layers, one of which appears to possess
a muscular power. These facts are developed by the microscope, which
also discloses numerous little bodies adhering to the internal membrane.
The fluid in the bladder is usually clear but occasionally turbid, and
then it has been found to contain a number of minute worms.
_Treatment._ This is deemed an almost incurable disorder. Where the
hydatid is not imbedded in the brain, its constant pressure, singularly
enough, causes a portion of the cranium to be absorbed, and finally the
part immediately over the hydatid becomes thin and soft enough to yield
under the pressure of the finger.
When such a spot is discovered, the English veterinarians usually
dissect back the muscular integuments, remove a portion of the bone,
carefully divide the investing membranes of the brain, and then, if
possible, remove the hydatid whole; or, failing to do this, remove its
fluid contents. The membranes and integuments are then restored to their
position, and an adhesive plaster placed over the whole. The French
veterinarians usually simply puncture the cranium and the cyst with a
trochar, and laying the sheep on its back, allow the fluid to run out
through the orifice thus made. A common awl would answer every purpose
for such a puncture; and the puncture is the preferable method for the
unskilled practitioner. An instance is, indeed, recorded of a cure
having been effected, where the animal had been given up, by boring with
a gimlet into the soft place on the head, when the water rushed out,
and the sheep immediately followed the others to the pasture.
When, however, the hazard and cruelty attending the operation, under the
most favorable circumstances, are considered, as well as the conceded
liability of a return of the malady--the growth of new hydatids--it is
evident that in this country, it would not be worth while, except in the
case of uncommonly valuable sheep, to adopt any other remedy than
depriving the miserable animal of life.