J. F.
SHIRLAW
343
These, however , are the most important points of comment :—no previous
case of equine encephalomyelitis, so far as one is aware, had ever occurred in
Jullundur. The horses of the 13th Lancers on their way from Multan to
Jullundur had been rigorously quarantined en route. There was, therefore,
no conceivable possibility that the three cases noted early in 1935 and also the
main outbreak of January (1936) were in any way connected with a fresh
infection. The only possibility that remains, therefore, is that ' carriers'
existed in the regiment.
The study of the subsequent history of the horses of the 13th Lancers at
Jullundur afforded two valuable items of information. The epizootology and
clinical syndrome noted during the course of this outbreak of equine encepha-
lomyelitis corresponded exactly with that observed at Multan and one is
therefore justified in concluding that they are specific of the disease. ' The
estion of carriers '—strongly stressed by Heane on prima facie evidence at
ltan—' cannot be ignored ' and there seems no other feasible explanation
ich can be accepted, or for which there are any grounds, to account for the
ond outbreak in this regiment.
.—THE CLINOLOGY DURING (a) THE COURSE OF THE OUTBREAKS AND (b)
SPORADIC CASES
In the earlier outbreaks, so mystifying and variable was the syndrome, so
peculiar the epizootic and pre-disposing factors, so negative the post-mortem
findings—apart from a fairly constant gastroenteritis—that it is not surprising
that the earlier observers were inclined to ascribe the disease to unidentifiable
plant and fodder poisoning. The tendency of certain Indian fodders and
grasses (e.g. sorghum) to be toxicogenic (cyanogenetic glucosides) at about
the time when the disease made its appearance, lent a very strong, if circum-
stantial, support to the toxicological theory. The symptoms were, therefore,
in common with most obscure plant poisonings, described as indefinite, with a
tendency to cerebral manifestation.
During the years 1923-33, when equine encephalomyelitis was first diag-
nosed, the disease was described as paraplegia or simply paralysis in the milder
cases—many of which recovered—and cerebral meningitis in the severe cases
which were usually fatal. Several of the mild paraplegia cases were noted to
progress, or relapse, to the acute cerebral phase. Generally, the majority of
cases were paraplegic, of varying degree, and while some apparently made an
uneventful recovery, others, progressive cases, had to be destroyed as hopeless.
The ratio of recoveries to hopeless cases was variable in each outbreak.
In the outbreak at Saharanpur (1923 September—December), fourteen
horses were affected, only one showed acute cerebral symptoms at the onset,
five progressed from a mild paraplegia to the cerebral type within two to three
days and seven were destroyed as hopeless cases, all of them showing progres-
sive symptoms.
At Saharanpur again (September—November, 1930), there were twenty-
eight cases, with seven recorded deaths, although the report ends with many
cases showing ' no improvement '. It is not known how many of these were
ultimately destroyed. Eleven horses showed cerebral symptoms, the majority
of which developed from early symptoms of paraplegia. Only one was, at the
outset, affected with meningo-encephalitis.
D 2