Fig. 221.—Diagrammatic section of a gid bladder-worm (Cœnurus cerebralis). a, Normal disposition of scolex; b, c, d, e, diagrammatic drawing to show the homology between cysticercus and cœnurus. (After Railliet.)
Prognosis. The prognosis is grave, and very few animals recover. Zürn estimated the cases of recovery in flocks at 2 per cent. In these cases the cysts degenerate and disappear.
Treatment. At the present moment there is no really practical curative treatment.
The best plan appears to be to trephine the skull and remove the cyst, provided its exact position can previously be determined. That, however, is the great difficulty. Its solution presupposes a perfect knowledge of the central nervous system and of the real purport of any apparent symptoms.
On the other hand, in sheep at least, the position of the cyst must always remain somewhat uncertain, because there are generally several, and the symptoms are of a mixed character.
The only treatment, therefore, which would be likely to succeed is difficult to carry out, and more difficult in the ox than in the sheep because of the great development of the frontal sinuses.
It has been mentioned that under exceptional circumstances the cœnurus, if very superficially placed, may cause atrophy of the cranial wall in the sheep by the outward pressure it exerts, and that the points of least resistance may be detected by the touch. In such cases intervention is necessary and is greatly facilitated; but they must be extremely rare, and Moussu declares he has never seen one.
Hartenstein has suggested continuous cooling of the cranium by irrigation or by applications of ice, the local lowering of temperature serving to impede the development of the cœnurus. This method should be tried in animals of high value, and, if the symptoms have not yet become too alarming, recovery is possible. On the other hand, when the symptoms indicate the presence of an old-standing cyst, there is little chance of success. Moreover, the treatment could not be applied where a large number of animals are affected.
It is much better to send the animals to the butcher if they are in good condition. In Scotland, however—particularly in Caithness—operation is said to be frequently practised with success.