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Sometimes, during the foot and mouth epizootic in the Ukraine,
the unaffected farms, situated at long distances from the affected
regions, were known to have been attacked by the virus as a result
of transmission of the infection through forage ( hay, green fodder,
etc.).

A definitely active role was played in transmission of the
virus from regions infected by foot and mouth disease to unaffected
farms by animals which were immune to this infection ( namely cats
and dogs ) as well as, wild birds. A case has been known where
foot and mouth infection was introduced into a farm, so far free
from the infection, by rocks during the winter period. This has
been proved by the fact that a very heavy snow fall in this parti-
cular farm area had completely cut it off from the surrounding
inhabited regions, in other words, the only possible source of the
foot and mouth infection was the rocks.

Literature has given a lot of information which proves that
the Artiodactyla plays an important role in the propagation of
foot and mouth disease.

In one of the farms of the Sumskaya regions, V. P. Litvin
( 1968 ) observed a case where foot and mouth infection was trans-
mitted through a sick moose, which before the infection was dis-
covered, grazing for some time with a group of young cattle in a
pasture, S. I. Dzhupin ( 1965 ) also mentions the importance of
wild Artiodactyla in transmitting the foot and mouth infection in
the Novosibirsk regions.

The protracted virulence of foot and mouth virus and the
active virus carried animals who had been affected by the disease,
is a very important factor in the spread of the infection. Thus,
according to the data of O. L. Skomorokhov ( 1952 ), a foot and
mouth virus was observed in the urine of an animal 146 days after
it was proclaimed clinically free of the disease. S. I. Dzhupin
( 1965 ) informs us that animals which had developed the foot and
mouth disease were carriers for a period of 3 to 12 months after
they were considered clinically healthy.

In our estimations, 7% of the foot and mouth epizootic cases
were caused by animal virus carriers. The extended period of
infection, due to the foot and mouth infection in some farms of
the Khmel'nic'kaya region may be explained by the fact that stock
which had suffered from the disease was mixed with groups of
mature cattle which had not been affected so far. It has been
established that the animals which had recovered from the foot
and mouth disease remained carriers of the virus for a period of
17 to 18 months. Thus, the cause of the foot and mouth disease
in 1967 among the animals of the Derazhnyanskaya department of
the "Zagotskotvidgodivlya" ("State purchasers of animal food")
(Vinnichnij region), were pigs brought in for fattening from the

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