J. F. SHIRLAW AND P. R.
KRISHNA
IYER
193
one month similarly did not influence its reactivity. One point worthy of mention is the irregular
and unpredictable reaction in Kumaoni cattle in the plains at Izatnagar. The virus could not be
propagated in cattle during the summer months, while in winter the reactions did not materially
differ from those encountered in cattle at Mukteswar. Kumaoni cattle are also susceptible to the
inoculation of blood of cattle reacting to the subcutaneous inoculation of crude lymph virus. In
the first test, two cattle were subcutaneously inoculated with 5 c.c. blood from a routine virus pro-
ducer at the 15th day of reaction. One animal reacted as typically as if inoculated with fresh
lymph virus and the second failed to react. In the second test, three cattle were similarly inoculated
with blood from a second virus producer; the first animal was inoculated at the 3rd day of reaction,
the second at the 9th and the third at the 14th day. All three test cattle reacted typically with
incubation period of eight, fourteen and eleven days and the interval, between inoculation and death
fifteen, twenty five and twenty days respectively. The test was repeated with blood from a third
virus producer with negative results. Kumaoni cattle proved susceptible to the intravenous inocula-
tion of crude lymph virus; seven animals were thus inoculated with 5 c.c. virus and only one failed
to react. Four animals developed acute pleuropneumonia with typical lesions of the disease, the
virus being readily isolated. The incubation period of the four cases averaged four to five days
and the interval between inoculation and death was twenty-six days. Two animals succumbed
to acute piroplasmosis during the period of reaction
A preliminary attempt in three cattle to transmit the disease by liberally spraying the nares
with fresh lymph virus failed, no reaction being observed over a period of two months. According
to Campbell [1938], pleuropneumonia may be fairly easily transmitted to susceptible cattle following
exposure in a well-sealed room to an atmosphere heavily sprayed with fresh virus. An attempt to
confirm this work in susceptible kumaoni cattle failed. Four cattle were placed in a room of 810
Cu. ft. dimension, which was then heavily sprayed by means of an electrically operated paint spray
gun with 1200 c.c. fresh lymph virus. The room was hermetically sealed for 24 hours and then
opened. The test animals were observed for six months, but none showed any sign of having acquired
infection, nor were any lesions of the disease seen at post-mortem. To infect cattle by the intra-
tracheal route also proved impossible. One of three cattle as inoculated with 2 c.c. fresh lymph
virus developed an extensive local reaction with fever which was undoubtedly the result of faulty
inoculation; no sign of internal metastasis was seen on autopsy of this case. The remaining animals
showed no reaction over two months. In our experience, the disease is capable of spread by direct
contact. Six Kumaoni cattle were placed for 12 days with a Kumaoni bull which was infected and
subsequently died of extensive pleuropneumonia. Three months later two of the six cattle exposed
to infection were noticed to be emaciated and coughing. In both cases severe lesions of contagious
pleuropneumonia were found at post-mortem. Kumaoni cattle could not be infected by feeding
the Assam 1 virus. Three animals were drenched with 100 c.c. fresh virus and no reaction was
observed over a period of six months.
Kumaoni cattle subcutaneously inoculated with Assam 2 virus reacted as cattle in the Assam
1 virus series; the number of cattle inoculated was, however, much less (seven as comparesd with
fifty-three). The incubation period ranged from 5-14 days, and the reaction period averaged 6.8
days.
As previously mentioned, two vaccine strains (Nos. 173 and 264) were received from Australia.
In the first batch of Kumaoni cattle subcutaneously inoculated with these two strains, two cattle
reacted strongly to vaccine strain 264, and the lymph virus so obtained was serially passaged in 25
cattle, with the following results:
Incubation period
2-5 days . . . . . . . .
6-7 „ . . . . . . . .
No. reacting
17
6
Reacting period
6-15 days
9-15 „
Average
10.7 days
11.7 „
A 2