March, 1956]
SYED
MOHIYUDDEEN
17
the exact mode of its therapeutic action cannot be explained satisfactorily. (This
is subject to correction since the normal range of serum magnesium level in Malnad
cattle is not known).
Cerebrospinal nematodiasis
The cause of bovine paralysis and paraplegia, though prevalent as seasonal
enzootic in some Malnad tracts of Mysore State for several years, had remained
obscure because the investigations undertaken were limited to the search of etiolo-
gical factors of bacterial, viral or nutritional origin. None of the previous investiga-
tors seems to have attempted a detailed histopathological study of the cerebrospinal
system. The present study is, therefore, a new approach for the elucidation of the
etiology of the disease in this country. The pathological evidence, such as the
presence of fully developed larvae of a nematode observed in the softened portion
of the spinal cord and transverse sections of immature nematode in the histological
sections of the spinal cord with malacic lesions, seem to suggest that enzootic bovine
paralysis and paraplegia of some hilly tracts of Mysore State is very probably a form
of cerebrospinal nematodiasis. The larvae were sheathed forms but their exact
identity could not be determined from the larval and immature forms observed
in the cerebrospinal system. The causal nematode is probably a filarid worm.
All the work published so far on cerebrospinal nematodiasis of domestic animals
in Japan, Korea and Ceylon indicate that microfilaria of Setaria digitata whose
natural hosts are cattle, produce cerebrospinal nematodiasis in unnatural hosts
like, sheep, goats and horses. Innes [1952] is of the opinion that Setaria equina
might produce cerebrospinal nematodiasis in cattle and an unnatural host might
be necessary for this condition. At the same time Innes [1951] states that " most
text books on parasitology admit of great ignorance concerning the life cycle of
Setaria species and what they do in natural and unnatural hosts ". He also men-
tions that " some statements in Mukteswar reports imply the possibility that the
same disease of goats and cattle exists in different parts of India ". He also quotes
unpublished work of Jensen and Bracken [1950] wherein similar lesions have been
described in the sections of brain and spinal cord of cases of a peculiar haemorrhagic
encephalomalacia in cattle occurring in the U. S. A.
In the Malnad tracts of Mysore State, where bovine paraplegia is prevalent
in the form of enzootic, cattle and buffaloes are predominant and other species of
domestic ruminants like sheep and goats are rare. Horses are generally not found
in those parts and, therefore, the probability of Setaria equina being the causal
nematode can easily be ruled out. Of course the hilly and the heavy rainfall area
of Mysore State, where bovine paraplegia is prevalent is surrounded by dense forest,
abounding also in a variety of wild fauna, including herbivorous animals like deers,
antelopes, bisons, etc. as well as a large number of blood sucking insects. Bell
[1934] states that species Setaria labiotopapillosa occurs not only in the peritoneal
cavity of the ox but also in African buffaloes, and various species of deers and ante-
lopes. As cerebrospinal nematodiasis has been observed as a factor associated with
the causation of bovine paralysis in Mysore State, the author thinks that the nema-
tode is very probably a filariod worm. If the sheathed larvae encountered in this
condition were presumed to be of Setaria species, the possible explanation that could