J. F.
SHIRLAW
341
The following year at Jhansi (August 1927) a serious outbreak of ' tym-
panitic colic ' broke out in the horses of the regiment affected during the pre-
ceding year and the 31st Mule Transport Company. Within nine days, sixty
cases occurred, with ten deaths. This outbreak was ascribed to forage poison-
ing and guinea grass was considered a possible etiological factor. It appears
probable, from such meagre records as obtain, that the disease was a recrude-
scence of the disease noted during the previous year.
During January, 1930, fourteen cases of ' poisoning ' occurred among the
horses of the 22nd Field Battery R. A., Lucknow, of which one died, two
developed paraplegia and were destroyed, and eleven recovered. This out-
break, undoubtedly one of equine encephalomyelitis, was considered to be due
to soaked gram fed to the horses.
In the winter of 1930, Simpson investigated an outbreak of disease in
army horses at Rawalpindi. The symptoms were those commonly associated
with equine encephalomyelitis and the cause was ascribed to ratti seed poison-
ing. At about the same time, fourteen cases of a similar disease occurred at
the Remount Depot, Saharanpur. This outbreak was diagnosed as paraplegia
and the fodder incriminated as the source of origin.
The year 1933 saw the severest and most extensive outbreak of paraplegia
which has affected a cavalry regiment and a thorough investigation showed the
disease to be a true encephalomyelitis which does not differ in any vital respect
from the same disease which has given rise to a great wealth of literature in
other countries in recent years.
A second severe outbreak of equine encephalomyelitis occurred in the same
regiment during the winter of 1935-36, but no major epizootic has since occur-
red. Minor outbreaks, in which two or three horses may be affected, have,
however, been frequent during the last few years, while sporadic cases have,
undoubtedly, gained in frequency.
Equine encephalomyelitis appears firmly rooted in certain areas in India
which have now come to be looked upon as enzootic areas and there appears
no doubt that today the disease is on the increase.
III.—COMMENTARY ON THE SEQUELAE OF THE MULTAN OUTBREAK
The outbreak of equine encephalomyelitis in the horses of the 13th Lancers
at Multan has been described in some detail [Mosley, Heane and Shirlaw, 1934].
It commenced in November 1933 and terminated in March 1934, as spontane-
ously as it had started, a feature of all outbreaks of equine encephalomyelitis.
Seventy horses had been affected, twenty-one of which had either died or been
destroyed.
One is left in doubt, however, as to whether these figures represent the
total incidence of the disease and whether many horses did not pass through
a fleeting phase which escaped notice. In human poliomyelitis ' it is only
occasional cases, attributed by some at less than one per cent of the total
infected, which develop paralysis and are diagnosed as such '. (Hurst.)
In equine encephalomyelitis, which, as will be shown later is also a polio¬
encephalomyelitis, it is not irrational to believe that a similar phase in infec-
tion occurs. This belief is borne out by the observation that, when routine
D