DIFFICULTIES IN REMOVING CCENURUS CEREBRAL1S. 
135 
the same in both classes of animals, and consist of the peculiar position of the 
head, dilatation of one or both pupils, and abnormal movements, similar to 
tllOSG m sh66P 
In operating, the marked differences in the skull formation of the two 
classes of animals must, however, he borne in mind. In cattle the frontal 
sinuses extend over the greater part of the cranium, and only through them 
can the cerebral hemispheres be reached. Hence diagnosis and treatment 
meet with the same difficulties as in large-horned rams. Softening ol the 
external cranial plates evidently cannot occur here ; but the inner tempora 
plates are sometimes so bulged that they come in contact with the external 
plates. This may be discovered by percussion, and the position of the 
parasite localised by sounding the frontal and superior maxillary sinuses, 
using the metallic end of the percussion hammer. . , . A 
If an operation be deemed desirable, the frontal smus must hist be lep nnec, 
a soft point in the bony covering of the cranium may be discovered, and tre¬ 
phining or the trochar resorted to according to the rules previously given. 
F In cattle the disease often takes an acute course, rendering operation use ess. 
Nor if performed does it insure success, the result often depending on accidenta 
circumstances. Although observations of successful operations have been 
published (Cooper, Bertholet, and others), reports of unfavourable lesults aie 
“Arthe result is always uncertain, it is better to slaughter affected animals 
early, though treatment may be' attempted m particularly valuable breeding 
animals • i 
Treatment is strictly surgical. Albrecht, Merkt, and others claim to rave 
had a fair degree of success. Munch cured 8 cases out of 11 operated on , 
Merkt had 50 per cent, of recoveries. Only those animals should be selectee oi 
operation which (1) eat well and show no marked interference with sensation, 
and (2) which always turn towards the same side. 
The animal is cast and the operation performed with strict antiseptic pie- 
cautions. Merkt, who is supported by Albrecht, describes the mode of opera- 
tW An incision about li- inches long is made through the skin parallel with and 
distant I of an inch from the middle line. The incision should not be com¬ 
menced too high, as in that direction the two plates of the temporal bone le 
wider apart. At right angles to this incision a second, about 1 inch m length 
is madeand then the second longitudinal cut. An assistant, kneeling oehm 
the animal’s head, holds back the flap with a hook, the exposed periosteum is 
carefully removed and a hole about * inch in diameter is made with a 
trephine This exposes the inner or cranial plate ot the tempoial bone. 
Very often, liowevei, this cranial plate is in contact with the outer or has 
become absorbed ; if not it must be removed with the gouge or bone foiceps 
and bone screw, as it can seldom be reached with the trephine. In any 
case the trephine must be used cautiously, and the cut be made slowly, to 
prevent the instrument suddenly breaking through when near the end ot the 
cut and so injuring the brain. Where the second plate exists it is necessary 
to remove with bone forceps all the thin, softened portions of bone covering 
the cyst so as to facilitate removal of the bladder, which is often of aige 
81 Having at last produced a hole about | an inch in diameter, the brain will 
lie seen in favourable cases, to be pressing against the edges, and on incising 
the meninges the 'distended bladder will at once protrude. As soon as ns 
occurs the straw bedding should be removed from below the affected side of 
the head so as to allow it to descend and thus render removal of thegladder 
easier The cyst usually bursts spontaneously; if not it can be ruptured 
