206
BLOOD PICTURE IN RANIKHET DISEASE OF FOWLS [Vol. XX, Part III
no more centrifugation was done The time taken by the first one was reckoned
as the time required for the complete sedimentation of corpuscles. The corpus-
cular volume was directly read from the tubes.
RESULTS
Mean values of the readings in health and in disease and their statistical ana-
lysis are incorporated in Tables I and II respectively.
Two fowls died of Ranikhet disease on the fourth day before the collection
of blood. The readings of these fowls for the post-infection period are, therefore,
those taken on the third day after infection. All the other thirteen birds died on
the fifth day and showed characteristic leisons of Ranikhet disease. It would appear
from Table I that almost in every case there was a marked drop in the total eryth-
rocyte and leucocyte count during the disease, and along with this there was a fall
in the haemoglobin concentration. It was also observed that the fall in the leu-
cocyte count was accompanied by a high rise in the percentage of heterophiles and
a fall in that of lymphocytes. In healthy birds, on the other hand, the percentage
relationship between heterophiles and lymphocytes was found to be completely
reversed. There is no significant difference in the number of eosinophiles, mono-
cytes and basophiles during the disease. Corpuscular volume and the time taken
for the complete sedimentation of corpuscles showed a distinct variation in the post-
infection period.
Reference to Table II would show that the changes, in the total erythrocyte
and leucocyte counts, in haemoglobin concentration, in corpuscular volume, in
the time taken for complete sedimentation of corpuscles and in the percentages
of heterophiles and lymphocytes produced during the disease, are highly significant.
This, however, is not the case with the variations in the proportion of eosinophiles,
monocytes and basophiles.
DISCUSSION
It will be seen from the data presented in Tables I and II that the onset of
Ranikhet disease is clearly marked by leucopenia and a high rise in the percentage
of heterophiles. Eosinophiles, monocytes and basophiles exhibit no significant
variation. Lymphocytes, on the other hand, are very much reduced in number.
There is a distinct fall in the total erythrocyte count during the disease. Along
with this is observed a significant fall in the corpuscular volume and in the concentra-
tion of haemoglobin. The time taken for the complete sedimentation of cells is
also reduced.
It is already stated that detailed information regarding changes in the blood
picture of fowls suffering from Ranikhet disease is scanty. However, it is interest-
ing to note, as already stated, that the results embodied in this article are in con-
formity with those obtained by Lewis and Shope [1929] and Kernkamp [1939] in
hog cholera, Hammon and Enders [1939] in a virus disease of cats, Kirk and Collins
[1945] in ferret distemper and Verma [1947] in rinderpest in goats. In the light
of the above remarks it appears that leucopenia is not a condition that can be taken
as specific for any particular virus disease. On the other hand it may be stated
that perhaps in majority of the virus diseases haemopoitic tissues are affected in
such a manner as to produce leucopenia.