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THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY
[ I, II
rinderpest or cattle plague, but this proved to be equally valueless upon trial in
" Ranikhet disease ". It is of interest to note that in one experiment the virus
definitely survived the treatment with chloroform although this is held to be capa-
ble of rendering the virus of cattle plague inert.
IDENTITY OF " RANIKHET DISEASE ".
Since 1927, a not inconsiderable number of articles upon what would at any
rate appear to be closely related to " Ranikhet disease " have appeared in scientific
publications from many parts of the world. Of these mention may be made of
"Newcastle Disease" in England [Doyle, 1927]; "Avian Pseudopest" in Java
[Picard, 1928]; " Avian Pest " in the Philippine [Rodier, 1929]; " A New Malady
of Fowls due to a Filter-passing Virus " in Egypt [Lagrange, 1929]; and " A New
Poultry Disease " (" Geflugelseuche ") in Korea [Ochi and Hashimoto, 1929].
The results of early work which was in progress at this laboratory at the time
of the publication of Doyle's article [1927] had already suggested to Major R. F.
Stirling, then Officiating Pathologist at this Institute, the very considerable similar-
ity that appeared to exist between " Ranikhet disease " and " Newcastle disease."
The results of experiments carried out subsequently by the present writer have now
furnished him with definite confirmatory evidence indicating a very close similarity
between the two forms of affection, as noticeable in their contagious nature; the
high rate of mortality amongst affected birds (in the case of " Newcastle disease,"
Doyle estimates a mortality rate of about 100 per cent.); the infectivity of the in-
ternal organs and mouth exudate of diseased birds ; filterability of the virus ; the
not infrequent non-inoculability of the virus with blood; the respiratory symp-
toms ; and in the post-mortem findings, e.g., the occurrence of localized catarrhal
enteritis in the duodenum, caecum or cloaca. On the other hand, the almost con-
sistent absence of febrile symptoms in " Ranikhet disease " constitutes a notable
point of difference between this and " Newcastle disease," whilst the average in-
cubation period in the latter affection, as given by Doyle, is also slightly longer
than that observed in " Ranikhet disease."
A striking proof that " Ranikhet disease " is, at any rate, immologically
identical with " Newcastle disease " of England and also with " Avian pest " in the
Philippine Islands has been afforded by a comparative test of the three viruses
at Muktesar.* It will be observed from the results summarized in the table
* The writer desires to express his sincere gratitude to Dr. Rodier, Pathologist, Veterinary Re-
search Laboratories, Minala, for providing him with samples of the viruses of both " Newcastle
disease " and " Avian pest," the former having been previously obtained by Dr. Rodier from England
from Mr. Doyle. These samples were despatched to the writer in India in cold storage all the way
from Manila, and the courtesy with which Dr. Rodier has attended to the writer's requests in this
connection is eloquent of the spirit of co-operation existing amongst veterinary workers overseas.