16
ENZOOTIC
BOVINE
PARAPLEGIA
[Vol. XXVI, Part I,
the possibility of latent trypanosomiasis not only blood smears from 32 ailing cases
were examined in detail for the presence of trypanosomes, but also smears made
from 8 samples of cerebrospinal fluid after centrifugation were examined. None
of these revealed any indication of trypanosomes. Besides, 10 samples of serum
from typical ailing cases were subjected to stilbamidine test (chemical test for surra)
and all were found negative, except one which developed doubtful reaction.
Blood from two typical ailing cases of paraplegia was drawn and immediately
injected into guineapigs and rabbits intraperitoneally. These guineapigs were
maintained for more than a month and their blood smears were examined every
day for trypanosomes with negative results. Thus all tests, viz. microscopic biolo-
gical and chemical, for detection of trypanosomiasis having yielded negative results
definitely ruled out the possibility of latent trypanosomiasis.
Virus etiology of the disease
Virus, as the probable etiological factor, was sometimes thought of in connec-
tion with this obscure disease. During the investigation the disease could not be
produced experimentally in bull calves, rabbits and guineapigs by injecting fresh
blood and emulsions of brain and spinal cord from typical cases of paraplegia indica-
ting that the causal agent if it was virus, was not present in blood or brain and spinal
cord of the affected animals. Although many animals died of the disease at one
time in the same place, observations made in the field did not indicate that the
disease was infectious in nature, tending to spread from one animal to another by
contact.
The epidemiological features of the disease were highly suggestive of some
insect vector playing some role in transmitting the disease. Two varieties of blood
sucking flies one fairly large sized and the other small, were examined and found to
belong to the genus—Tabanus. Whether these flies or other insects played any
role in transmitting the disease from one animal to another cannot be asserted at
this stage as the investigation on all aspects of the disease is not yet complete.
Hypo-calcaemia and hypomagnesiumia
During the investigation of this disease in Mysore State 11 cases (3 acute and
8 subacute) were treated with calcium borogluconate and magnesium sulphate in
Nagar and Sagar areas during the months of May, June, July, August and Septem-
ber 1954. Of the 11 typical cases of bovine paraplegia treated, 6 subacute and
chronic cases improved and gradually recovered, while the five acute and subacute
cases did not improve and died even after treatment. Nine out of 10 serum samples
from 10 ailing cases on chemical analysis did not reveal any calcium deficiency and
only one had low calcium level. Serum magnesium level was within normal range
in 4 cases and slightly low in the remaining six cases. There was no indication
of phosphorus deficiency in any of the 10 cases. The beneficial effect of calcium
and magnesium in 6 out of 11 cases and insignificantly low magnesium level in blood
of 6 out of 10 cases studied seem to suggest that if at all any mineral deficiency had
some bearing on precipitating the course of the disease, it is in all probability
magnesium deficiency. If this be so, how magnesium supplement by way of 2 or 3
injections could rectify the damage already done to the cerebrospinal system, and