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Kolkhose, named after Petrovskij, which had been attacked by the
foot and mouth disease as far back as March, 1966. In the Khar-
kovitz section of the Starosinyav'skij beetroot farm, the mature
cattle had contracted foot and mouth disease, 17 months after the
previously infected animals had been clinically cleared of the
disease. The source of the infection was animal - virus carrier
of the same Sovkhose. The data collected by us proves that the
animals which had suffered from foot and mouth disease should not
be mixed with healthy animals for at least 1.5 to 2 years after
being clinically cleared of the disease.

Sometimes the cause of fresh outbreaks of foot and mouth
disease, caused by A22 virus in farms so far unaffected by the
disease, at the commencement of the foot and mouth epizootic in
the Ukraine, was the lymph of foot and mouth vaccine, which had
an excessive residual virulence. Therefore after animals were
vaccinated in farms which were unaffected by the disease, very
often fresh foot and month outbreaks were observed.

According to our ( epizootological ) data, the virus carriers
and virulence which is sometimes active for approx. 17 to 18
months in animals which had developed foot and mouth disease is
an ever present danger.

The study of the epizootological nature of the animal farms
have shown that foot and mouth epizootic in the Ukraine, caused
by the A22 virus, ( 1965-1966 ), travelled with lightning speed.
Later, with every passing year, the force of the epizootic was
reduced, till finally the epizootic foot and mouth disease was
observed only as individual outbreaks. A deciding role in putt-
ing an end to foot and mouth epizootic in the Ukraine was the
complex of anti-foot and mouth disease protective measure ( such
as quarantine, veterinary, hygienec, etc. ) but, first and
foremost the method of immunization of animals susceptible to
foot and mouth infection.

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