RU2320324C1 - Method for preventing infectious cattle rhinotracheitis in calves with the help of antiviral preparation iodoantipyrine - Google Patents

Abstract

FIELD: veterinary virology.

SUBSTANCE: calves should be fed with milk supplemented with antiviral preparation iodoantipyrine per 2 g once daily for 5 d. The innovation enables to decrease the degree of manifestation of clinical signs of respiratory disease in calves and infectious activity of the virus.

EFFECT: higher efficiency of prophylaxis.

1 ex, 1 tbl

Description

The invention relates to veterinary virology, and in particular to methods of preventing viral diseases of farm animals using antiviral drugs.

A known method for the prevention of cattle IRT using the antiviral drug isatizone (See RF Patent No. 2196574, class 7 A61K 31/00, A61P 11/00). This method comprises treating animals aerosol formulation, which is carried out twice with an interval of 24 hours, during picking groups of animals in the aerosol chamber, spraying per 1 m ³ chamber 2 ml of the drug, and the drug dose is calculated by the formula:

D = T × C × V,

Where

D is the dose of the drug in mg;

C is the concentration of the drug in mg / l;

T is the time spent by animals in the aerosol, min;

V - respiratory capacity of the lungs (l / min).

This method allows to prevent the development of infectious rhinotracheitis in cattle, increase safety and increase live weight gain.

The disadvantage of this method is the scheme of the drug using aerosol generators, which is not always possible in practical conditions and the need to build aerosol chambers.

The most acceptable from the point of view of the described shortcomings and adopted as a prototype is a method for the prevention of calves with respiratory syndrome using the drug iodantipyrine (1-phenyl-2,3-dimethyl-4-iodopyrazolone, R-pyrazolone) (Instructions for use of iodantipirin. MOH and MP RF, 1996). The method involves drinking milk of the specified drug in a dose of 0.02 g / kg live weight 2 times a day for 4 days, for 6 days, 0.01 g / kg of animal weight (Kashin A.S., Ospischev A.V. ., Sidorov VV et al. Efficiency of R-pyrazolone in the prevention and treatment of calves with respiratory syndrome. // Materials of the international scientific and practical conference “Current state and current problems of the development of veterinary science and practice” (15-16 September 2005), Almaty. - 2005. - S.179-182). The dose of the drug in the proposed method is 0.02 g / kg of live weight, the drug is given to animals 2 times a day for 4 days, for 6 days at 0.01 g / kg of animal weight. Thus, the duration of administration of the drug to calves for prophylactic purposes is 10 days.

The disadvantage of this method is a rather long period of drinking the drug (more than 10 days).

The objective of the invention is the prevention and reduction of the severity of the clinical signs of infectious rhinotracheitis in cattle with calves using an antiviral drug.

The problem is solved in that in the known method for the prevention of infectious rhinotracheitis of cattle in calves, including feeding the animal the antiviral drug iodantipyrine with milk, according to the invention, the drug is drunk 2 g once a day for five days.

The invention is illustrated by the following example.

Example 1

To determine the prophylactic effectiveness of the drug iodantipyrine, two experimental and one control group of calves were formed on the basis of analogues of 6 animals in each.

The calves of the experimental group 1 were fed a preparation with milk of 2 g per animal for five days, and the calves of the experimental group 2 - 0.02 g / kg of the animal’s weight 2 times a day for 4 days and 0.01 g / kg 2 once a day for 6 days. Then, the animals of the experimental groups were infected intranasally with the infectious rhinotracheitis virus (strain C11) using the aerosol generator BG-2. At the same time, the calves of the control group who did not receive the drug were infected.

The animals were clinically monitored, nasal secretions and blood serum were taken. The presence of the virus in the nasal secretions of calves was determined before feeding the drug and then within 15 days from the moment of infection. Infectious activity of the virus was expressed in lg TCD _{50 / 0.1 ml} .

Evaluation of the preventive effect of the drug was carried out according to the degree of manifestation of clinical signs, a decrease in infectious activity and the duration of virus isolation with nasal secretions of calves after experimental infection.

The results are presented in table 1.

Table 1. Group of animals (n = 6) The degree of manifestation of clinical signs of acute respiratory disease Infectious bovine rhinotracheitis virus infectious activity in nasal secretions calves, lg TCD _{50 / ml 0.1} (M ± m) Duration of virus isolation with nasal secrets of calves, days Case, number of goals Experienced 1 Low 2.75 ± 0.12 13 0 Experienced 2 Average 4.75 ± 0.24 19 2 Control High 6.67 ± 0.13 19 5

After experimental infection, the calves of experimental group 1 showed a low degree of clinical signs of acute respiratory disease, characterized by a short-term increase in body temperature, the maximum values of which were 40.5 ° C for 6-7 days, slight inhibition of the general condition, sneezing, and weak serous rhinitis.

In calves of experimental group 2, the average degree of manifestation of clinical signs of acute respiratory disease.

In control animals, a high degree (depression of the general condition, fever up to 42.5 ° C; serous discharge from the nose, catarrhal conjunctivitis, lacrimation, sneezing and coughing). The maximum rise in body temperature was 9 days after infection (42.5 ° C). In control calves, the virus was isolated on day 2 after infection, the highest titers of the virus were detected on day 5 (6.67 ± 0.13 lg TCD _{50 / 0.1 ml} ). Reduction of infectious activity of the virus in nasal secretions calves occurred by Day 15 2.5 ± 0.07 to lg TCD _{50 / 0.1 ml.}

The maximum titers of the IRT virus of cattle in calves of experimental group 1 were recorded on day 7 2.75 ± 0.12 lg TCD _{50 / 0.1 ml} after infection. By 10 days post infection the animals showed a decrease of virus titer allocated to 1.25 ± 0.12 lg TCD _{50 / 0.1 ml} (P <0.05).

In calves of experimental group 2, the maximum titers of the virus were 4.75 ± 0.24 lg TCD _{50 / 0.1 ml} .

Thus, in animals of experimental group 1, which were fed the antiviral drug iodantipirin 2 g once a day for 5 days with their subsequent infection, the severity of the clinical signs of the disease decreased, the infectious activity of the virus on day 10 by 1.5 lg TCD _{50 / 0.1 ml} and reduced the time of virus isolation with nasal secretions of calves by 6 days compared with experimental 2 and control groups of animals.

Thus, the proposed method for the prevention of infectious rhinotracheitis in cattle reduces the degree of manifestation of clinical signs of respiratory disease in calves, reduces the time it takes to isolate the virus with nasal secretions, reduces the infectious activity of the virus and has the prospect of preventing infectious rhinotracheitis in cattle.

Claims (1)

A method for the prevention of infectious rhinotracheitis in cattle in calves, comprising feeding the animals with milk the antiviral drug iodantipyrine, characterized in that the preparation is fed to the calves 2 g once a day for five days.