RANIKHET DISEASE : A NEW DISEASE OF FOWLS IN INDIA DUE
         TO A FILTER-PASSING VIRUS.*

                           BY

                  HUGH COOPER, M.R.C.V.S., I.V.S.,

         Veterinary Research Officer, Imperial Institute of Veterinary Research,

                           Muktesar-Kumaun.
                           (With 10 charts.)

         The earliest mention of the disease described in this paper occurs in the Annual
Report of the Muktesar Institute for 1927-28, where, under the heading " A New
Fowl Disease," Dr. Edwards refers to an exceptionally heavy outbreak of disease
in July, 1927, which accounted for about 400 highly bred fowls, within the brief
space of two months, out of a flock of about 600 on a farm at Ranikhet, a neigh-
bouring station to this Institute situated in the Kumaun foot-hills of the Himalayas.
The two characteristic features of the disease stressed by Dr. Edwards were " the
almost entire absence of lesions" and the non-inoculability of the virus with the
blood of infected birds, although it was " readily conveyed with filterates of mouth-
washings ".

         Towards the latter part of 1928, the disease was diagnosed in a number of sick
fowls forwarded to this Institute by a private poultry-owner in the Carhwal district
of the United Provinces. Again, in January and April of last year, 1929, the disease
occurred in two separate outbreaks on the farm of the United Provinces Poultry
Association at Lucknow, and the identity of the disease in one at least of these
outbreaks with " Ranikhet Disease " was confirmed from examination of infected
fowls at the Muktesar Laboratory.

         Infective material thus became available at this Institute from each of the
three outbreaks referred to above, and advantage was taken of the opportunities
thus afforded to carry out a study of the disease under laboratory conditions.

         A brief reference to this work was included by the writer in the Annual Report
of the Muktesar Institute, 1928-29, and the present paper includes results obtained
since 1927 from the study, which is still in progress.

         Outbreaks of what would appear to be the same disease—for its identity can
hardly be mistaken despite the frequently meagre clinical details available—have
also been reported from a large number of widely separated localities in India,
and even appeals for help in combating the outbreaks have been noticed in the
correspondence columns of Indian newspapers.

         *Paper submitted to World Poultry Congress, 1930.

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